import {Component} from "../Component.js";
import {math} from "../math/math.js";
import {buildEdgeIndices} from '../math/buildEdgeIndices.js';
import {SceneModelMesh} from './SceneModelMesh.js';
import {DTXLayer} from './layer/DTXLayer.js';
import {VBOLayer} from './layer/VBOLayer.js';
import {ENTITY_FLAGS} from './ENTITY_FLAGS.js';
import {RenderFlags} from "../webgl/RenderFlags.js";
import {worldToRTCPositions} from "../math/rtcCoords.js";
import {SceneModelTextureSet} from "./SceneModelTextureSet.js";
import {SceneModelTexture} from "./SceneModelTexture.js";
import {Texture2D} from "../webgl/Texture2D.js";
import {utils} from "../utils.js";
import {getKTX2TextureTranscoder} from "../utils/textureTranscoders/KTX2TextureTranscoder/KTX2TextureTranscoder.js";
import {
    ClampToEdgeWrapping,
    LinearEncoding,
    LinearFilter,
    LinearMipmapLinearFilter,
    LinearMipMapNearestFilter,
    MirroredRepeatWrapping,
    NearestFilter,
    NearestMipMapLinearFilter,
    NearestMipMapNearestFilter,
    RepeatWrapping,
    sRGBEncoding
} from "../constants/constants.js";
import {createPositionsDecodeMatrix, quantizePositions} from "./compression.js";
import {uniquifyPositions} from "./calculateUniquePositions.js";
import {rebucketPositions} from "./rebucketPositions.js";
import {SceneModelEntity} from "./SceneModelEntity.js";
import {geometryCompressionUtils} from "../math/geometryCompressionUtils.js";
import {SceneModelTransform} from "./SceneModelTransform.js";


const tempVec3a = math.vec3();

const tempOBB3 = math.OBB3();
const tempQuaternion = math.vec4();

const DEFAULT_SCALE = math.vec3([1, 1, 1]);
const DEFAULT_POSITION = math.vec3([0, 0, 0]);
const DEFAULT_ROTATION = math.vec3([0, 0, 0]);
const DEFAULT_QUATERNION = math.identityQuaternion();
const DEFAULT_MATRIX = math.identityMat4();

const DEFAULT_COLOR_TEXTURE_ID = "defaultColorTexture";
const DEFAULT_METAL_ROUGH_TEXTURE_ID = "defaultMetalRoughTexture";
const DEFAULT_NORMALS_TEXTURE_ID = "defaultNormalsTexture";
const DEFAULT_EMISSIVE_TEXTURE_ID = "defaultEmissiveTexture";
const DEFAULT_OCCLUSION_TEXTURE_ID = "defaultOcclusionTexture";
const DEFAULT_TEXTURE_SET_ID = "defaultTextureSet";

const defaultCompressedColor = new Uint8Array([255, 255, 255]);

const VBO_INSTANCED = 0;
const VBO_BATCHED = 1;
const DTX = 2;

/**
 * @desc A high-performance model representation for efficient rendering and low memory usage.
 *
 * # Examples
 *
 * Internally, SceneModel uses a combination of several different techniques to render and represent
 * the different parts of a typical model. Each of the live examples at these links is designed to "unit test" one of these
 * techniques, in isolation. If some bug occurs in SceneModel, we use these tests to debug, but they also
 * serve to demonstrate how to use the capabilities of SceneModel programmatically.
 *
 * * [Loading building models into SceneModels](/examples/buildings)
 * * [Loading city models into SceneModels](/examples/cities)
 * * [Loading LiDAR scans into SceneModels](/examples/lidar)
 * * [Loading CAD models into SceneModels](/examples/cad)
 * * [SceneModel feature tests](/examples/scenemodel)
 *
 * # Overview
 *
 * While xeokit's standard [scene graph](https://github.com/xeokit/xeokit-sdk/wiki/Scene-Graphs) is great for gizmos and medium-sized models, it doesn't scale up to millions of objects in terms of memory and rendering efficiency.
 *
 * For huge models, we have the ````SceneModel```` representation, which is optimized to pack large amounts of geometry into memory and render it efficiently using WebGL.
 *
 * ````SceneModel```` is the default model representation loaded by  (at least) {@link GLTFLoaderPlugin}, {@link XKTLoaderPlugin} and  {@link WebIFCLoaderPlugin}.
 *
 * In this tutorial you'll learn how to use ````SceneModel```` to create high-detail content programmatically. Ordinarily you'd be learning about ````SceneModel```` if you were writing your own model loader plugins.
 *
 * # Contents
 *
 * - [SceneModel](#DataTextureSceneModel)
 * - [GPU-Resident Geometry](#gpu-resident-geometry)
 * - [Picking](#picking)
 * - [Example 1: Geometry Instancing](#example-1--geometry-instancing)
 * - [Finalizing a SceneModel](#finalizing-a-DataTextureSceneModel)
 * - [Finding Entities](#finding-entities)
 * - [Example 2: Geometry Batching](#example-2--geometry-batching)
 * - [Classifying with Metadata](#classifying-with-metadata)
 * - [Querying Metadata](#querying-metadata)
 * - [Metadata Structure](#metadata-structure)
 * - [RTC Coordinates](#rtc-coordinates-for-double-precision)
 *   - [Example 3: RTC Coordinates with Geometry Instancing](#example-2--rtc-coordinates-with-geometry-instancing)
 *   - [Example 4: RTC Coordinates with Geometry Batching](#example-2--rtc-coordinates-with-geometry-batching)
 *
 * ## SceneModel
 *
 * ````SceneModel```` uses two rendering techniques internally:
 *
 * 1. ***Geometry batching*** for unique geometries, combining those into a single WebGL geometry buffer, to render in one draw call, and
 * 2. ***geometry instancing*** for geometries that are shared by multiple meshes, rendering all instances of each shared geometry in one draw call.
 *
 * <br>
 * These techniques come with certain limitations:
 *
 * * Non-realistic rendering - while scene graphs can use xeokit's full set of material workflows, ````SceneModel```` uses simple Lambertian shading without textures.
 * * Static transforms - transforms within a ````SceneModel```` are static and cannot be dynamically translated, rotated and scaled the way {@link Node}s and {@link Mesh}es in scene graphs can.
 * * Immutable model representation - while scene graph {@link Node}s and
 * {@link Mesh}es can be dynamically plugged together, ````SceneModel```` is immutable,
 * since it packs its geometries into buffers and instanced arrays.
 *
 * ````SceneModel````'s API allows us to exploit batching and instancing, while exposing its elements as
 * abstract {@link Entity} types.
 *
 * {@link Entity} is the abstract base class for
 * the various xeokit components that represent models, objects, or anonymous visible elements. An Entity has a unique ID and can be
 * individually shown, hidden, selected, highlighted, ghosted, culled, picked and clipped, and has its own World-space boundary.
 *
 * * A ````SceneModel```` is an {@link Entity} that represents a model.
 * * A ````SceneModel```` represents each of its objects with an {@link Entity}.
 * * Each {@link Entity} has one or more meshes that define its shape.
 * * Each mesh has either its own unique geometry, or shares a geometry with other meshes.
 *
 * ## GPU-Resident Geometry
 *
 * For a low memory footprint, ````SceneModel```` stores its geometries in GPU memory only, compressed (quantized) as integers. Unfortunately, GPU-resident geometry is
 * not readable by JavaScript.
 *
 *
 * ## Example 1: Geometry Instancing
 *
 * In the example below, we'll use a ````SceneModel````
 * to build a simple table model using geometry instancing.
 *
 * We'll start by adding a reusable box-shaped geometry to our ````SceneModel````.
 *
 * Then, for each object in our model we'll add an {@link Entity}
 * that has a mesh that instances our box geometry, transforming and coloring the instance.
 *
 * [![](http://xeokit.io/img/docs/sceneGraph.png)](https://xeokit.github.io/xeokit-sdk/examples/index.html#sceneRepresentation_SceneModel_instancing)
 *
 * ````javascript
 * import {Viewer, SceneModel} from "xeokit-sdk.es.js";
 *
 * const viewer = new Viewer({
 *     canvasId: "myCanvas",
 *     transparent: true
 * });
 *
 * viewer.scene.camera.eye = [-21.80, 4.01, 6.56];
 * viewer.scene.camera.look = [0, -5.75, 0];
 * viewer.scene.camera.up = [0.37, 0.91, -0.11];
 *
 * // Build a SceneModel representing a table
 * // with four legs, using geometry instancing
 *
 * const sceneModel = new SceneModel(viewer.scene, {
 *     id: "table",
 *     isModel: true, // <--- Registers SceneModel in viewer.scene.models
 *     position: [0, 0, 0],
 *     scale: [1, 1, 1],
 *     rotation: [0, 0, 0]
 * });
 *
 * // Create a reusable geometry within the SceneModel
 * // We'll instance this geometry by five meshes
 *
 * sceneModel.createGeometry({
 *
 *     id: "myBoxGeometry",
 *
 *     // The primitive type - allowed values are "points", "lines" and "triangles".
 *     // See the OpenGL/WebGL specification docs
 *     // for how the coordinate arrays are supposed to be laid out.
 *     primitive: "triangles",
 *
 *     // The vertices - eight for our cube, each
 *     // one spanning three array elements for X,Y and Z
 *     positions: [
 *          1, 1, 1, -1, 1, 1, -1, -1, 1, 1, -1, 1, // v0-v1-v2-v3 front
 *          1, 1, 1, 1, -1, 1, 1, -1, -1, 1, 1, -1, // v0-v3-v4-v1 right
 *          1, 1, 1, 1, 1, -1, -1, 1, -1, -1, 1, 1, // v0-v1-v6-v1 top
 *          -1, 1, 1, -1, 1, -1, -1, -1, -1, -1, -1, 1, // v1-v6-v7-v2 left
 *          -1, -1, -1, 1, -1, -1, 1, -1, 1, -1, -1, 1, // v7-v4-v3-v2 bottom
 *          1, -1, -1, -1, -1, -1, -1, 1, -1, 1, 1, -1 // v4-v7-v6-v1 back
 *     ],
 *
 *     // Normal vectors, one for each vertex
 *     normals: [
 *         0, 0, 1, 0, 0, 1, 0, 0, 1, 0, 0, 1, // v0-v1-v2-v3 front
 *         1, 0, 0, 1, 0, 0, 1, 0, 0, 1, 0, 0, // v0-v3-v4-v5 right
 *         0, 1, 0, 0, 1, 0, 0, 1, 0, 0, 1, 0, // v0-v5-v6-v1 top
 *         -1, 0, 0, -1, 0, 0, -1, 0, 0, -1, 0, 0, // v1-v6-v7-v2 left
 *         0, -1, 0, 0, -1, 0, 0, -1, 0, 0, -1, 0, // v7-v4-v3-v2 bottom
 *         0, 0, -1, 0, 0, -1, 0, 0, -1, 0, 0, -1 // v4-v7-v6-v5 back
 *     ],
 *
 *     // Indices - these organise the positions and and normals
 *     // into geometric primitives in accordance with the "primitive" parameter,
 *     // in this case a set of three indices for each triangle.
 *     //
 *     // Note that each triangle is specified in counter-clockwise winding order.
 *     //
 *     indices: [
 *         0, 1, 2, 0, 2, 3, // front
 *         4, 5, 6, 4, 6, 7, // right
 *         8, 9, 10, 8, 10, 11, // top
 *         12, 13, 14, 12, 14, 15, // left
 *         16, 17, 18, 16, 18, 19, // bottom
 *         20, 21, 22, 20, 22, 23
 *     ]
 * });
 *
 * // Red table leg
 *
 * sceneModel.createMesh({
 *     id: "redLegMesh",
 *     geometryId: "myBoxGeometry",
 *     position: [-4, -6, -4],
 *     scale: [1, 3, 1],
 *     rotation: [0, 0, 0],
 *     color: [1, 0.3, 0.3]
 * });
 *
 * sceneModel.createEntity({
 *     id: "redLeg",
 *     meshIds: ["redLegMesh"],
 *     isObject: true // <---- Registers Entity by ID on viewer.scene.objects
 * });
 *
 * // Green table leg
 *
 * sceneModel.createMesh({
 *     id: "greenLegMesh",
 *     geometryId: "myBoxGeometry",
 *     position: [4, -6, -4],
 *     scale: [1, 3, 1],
 *     rotation: [0, 0, 0],
 *     color: [0.3, 1.0, 0.3]
 * });
 *
 * sceneModel.createEntity({
 *     id: "greenLeg",
 *     meshIds: ["greenLegMesh"],
 *     isObject: true // <---- Registers Entity by ID on viewer.scene.objects
 * });
 *
 * // Blue table leg
 *
 * sceneModel.createMesh({
 *     id: "blueLegMesh",
 *     geometryId: "myBoxGeometry",
 *     position: [4, -6, 4],
 *     scale: [1, 3, 1],
 *     rotation: [0, 0, 0],
 *     color: [0.3, 0.3, 1.0]
 * });
 *
 * sceneModel.createEntity({
 *     id: "blueLeg",
 *     meshIds: ["blueLegMesh"],
 *     isObject: true // <---- Registers Entity by ID on viewer.scene.objects
 * });
 *
 * // Yellow table leg
 *
 * sceneModel.createMesh({
 *      id: "yellowLegMesh",
 *      geometryId: "myBoxGeometry",
 *      position: [-4, -6, 4],
 *      scale: [1, 3, 1],
 *      rotation: [0, 0, 0],
 *      color: [1.0, 1.0, 0.0]
 * });
 *
 * sceneModel.createEntity({
 *     id: "yellowLeg",
 *     meshIds: ["yellowLegMesh"],
 *     isObject: true // <---- Registers Entity by ID on viewer.scene.objects
 * });
 *
 * // Purple table top
 *
 * sceneModel.createMesh({
 *     id: "purpleTableTopMesh",
 *     geometryId: "myBoxGeometry",
 *     position: [0, -3, 0],
 *     scale: [6, 0.5, 6],
 *     rotation: [0, 0, 0],
 *     color: [1.0, 0.3, 1.0]
 * });
 *
 * sceneModel.createEntity({
 *     id: "purpleTableTop",
 *     meshIds: ["purpleTableTopMesh"],
 *     isObject: true // <---- Registers Entity by ID on viewer.scene.objects
 * });
 *  ````
 *
 * ## Finalizing a SceneModel
 *
 * Before we can view and interact with our ````SceneModel````, we need to **finalize** it. Internally, this causes the ````SceneModel```` to build the
 * vertex buffer objects (VBOs) that support our geometry instances. When using geometry batching (see next example),
 * this causes ````SceneModel```` to build the VBOs that combine the batched geometries. Note that you can do both instancing and
 * batching within the same ````SceneModel````.
 *
 * Once finalized, we can't add anything more to our ````SceneModel````.
 *
 * ```` javascript
 * SceneModel.finalize();
 * ````
 *
 * ## Finding Entities
 *
 * As mentioned earlier, {@link Entity} is
 * the abstract base class for components that represent models, objects, or just
 * anonymous visible elements.
 *
 * Since we created configured our ````SceneModel```` with ````isModel: true````,
 * we're able to find it as an Entity by ID in ````viewer.scene.models````. Likewise, since
 * we configured each of its Entities with ````isObject: true````, we're able to
 * find them in  ````viewer.scene.objects````.
 *
 *
 * ````javascript
 * // Get the whole table model Entity
 * const table = viewer.scene.models["table"];
 *
 *  // Get some leg object Entities
 * const redLeg = viewer.scene.objects["redLeg"];
 * const greenLeg = viewer.scene.objects["greenLeg"];
 * const blueLeg = viewer.scene.objects["blueLeg"];
 * ````
 *
 * ## Example 2: Geometry Batching
 *
 * Let's once more use a ````SceneModel````
 * to build the simple table model, this time exploiting geometry batching.
 *
 *  [![](http://xeokit.io/img/docs/sceneGraph.png)](https://xeokit.github.io/xeokit-sdk/examples/index.html#sceneRepresentation_SceneModel_batching)
 *
 * ````javascript
 * import {Viewer, SceneModel} from "xeokit-sdk.es.js";
 *
 * const viewer = new Viewer({
 *     canvasId: "myCanvas",
 *     transparent: true
 * });
 *
 * viewer.scene.camera.eye = [-21.80, 4.01, 6.56];
 * viewer.scene.camera.look = [0, -5.75, 0];
 * viewer.scene.camera.up = [0.37, 0.91, -0.11];
 *
 * // Create a SceneModel representing a table with four legs, using geometry batching
 * const sceneModel = new SceneModel(viewer.scene, {
 *     id: "table",
 *     isModel: true,  // <--- Registers SceneModel in viewer.scene.models
 *     position: [0, 0, 0],
 *     scale: [1, 1, 1],
 *     rotation: [0, 0, 0]
 * });
 *
 * // Red table leg
 *
 * sceneModel.createMesh({
 *     id: "redLegMesh",
 *
 *     // Geometry arrays are same as for the earlier batching example
 *     primitive: "triangles",
 *     positions: [ 1, 1, 1, -1, 1, 1, -1, -1, 1, 1, -1, 1 ... ],
 *     normals: [ 0, 0, 1, 0, 0, 1, 0, 0, 1, 0, 0, 1, ... ],
 *     indices: [ 0, 1, 2, 0, 2, 3, 4, 5, 6, 4, 6, 7, ... ],
 *     position: [-4, -6, -4],
 *     scale: [1, 3, 1],
 *     rotation: [0, 0, 0],
 *     color: [1, 0.3, 0.3]
 * });
 *
 * sceneModel.createEntity({
 *     id: "redLeg",
 *     meshIds: ["redLegMesh"],
 *     isObject: true // <---- Registers Entity by ID on viewer.scene.objects
 * });
 *
 * // Green table leg
 *
 * sceneModel.createMesh({
 *     id: "greenLegMesh",
 *     primitive: "triangles",
 *     primitive: "triangles",
 *     positions: [ 1, 1, 1, -1, 1, 1, -1, -1, 1, 1, -1, 1 ... ],
 *     normals: [ 0, 0, 1, 0, 0, 1, 0, 0, 1, 0, 0, 1, ... ],
 *     indices: [ 0, 1, 2, 0, 2, 3, 4, 5, 6, 4, 6, 7, ... ],
 *     position: [4, -6, -4],
 *     scale: [1, 3, 1],
 *     rotation: [0, 0, 0],
 *     color: [0.3, 1.0, 0.3]
 * });
 *
 * sceneModel.createEntity({
 *     id: "greenLeg",
 *     meshIds: ["greenLegMesh"],
 *     isObject: true // <---- Registers Entity by ID on viewer.scene.objects
 * });
 *
 * // Blue table leg
 *
 * sceneModel.createMesh({
 *     id: "blueLegMesh",
 *     primitive: "triangles",
 *     positions: [ 1, 1, 1, -1, 1, 1, -1, -1, 1, 1, -1, 1 ... ],
 *     normals: [ 0, 0, 1, 0, 0, 1, 0, 0, 1, 0, 0, 1, ... ],
 *     indices: [ 0, 1, 2, 0, 2, 3, 4, 5, 6, 4, 6, 7, ... ],
 *     position: [4, -6, 4],
 *     scale: [1, 3, 1],
 *     rotation: [0, 0, 0],
 *     color: [0.3, 0.3, 1.0]
 * });
 *
 * sceneModel.createEntity({
 *     id: "blueLeg",
 *     meshIds: ["blueLegMesh"],
 *     isObject: true // <---- Registers Entity by ID on viewer.scene.objects
 * });
 *
 * // Yellow table leg object
 *
 * sceneModel.createMesh({
 *     id: "yellowLegMesh",
 *     positions: [ 1, 1, 1, -1, 1, 1, -1, -1, 1, 1, -1, 1 ... ],
 *     normals: [ 0, 0, 1, 0, 0, 1, 0, 0, 1, 0, 0, 1, ... ],
 *     indices: [ 0, 1, 2, 0, 2, 3, 4, 5, 6, 4, 6, 7, ... ],
 *     position: [-4, -6, 4],
 *     scale: [1, 3, 1],
 *     rotation: [0, 0, 0],
 *     color: [1.0, 1.0, 0.0]
 * });
 *
 * sceneModel.createEntity({
 *     id: "yellowLeg",
 *     meshIds: ["yellowLegMesh"],
 *     isObject: true // <---- Registers Entity by ID on viewer.scene.objects
 * });
 *
 * // Purple table top
 *
 * sceneModel.createMesh({
 *     id: "purpleTableTopMesh",
 *     positions: [ 1, 1, 1, -1, 1, 1, -1, -1, 1, 1, -1, 1 ... ],
 *     normals: [ 0, 0, 1, 0, 0, 1, 0, 0, 1, 0, 0, 1, ... ],
 *     indices: [ 0, 1, 2, 0, 2, 3, 4, 5, 6, 4, 6, 7, ... ],
 *     position: [0, -3, 0],
 *     scale: [6, 0.5, 6],
 *     rotation: [0, 0, 0],
 *     color: [1.0, 0.3, 1.0]
 * });
 *
 * sceneModel.createEntity({
 *     id: "purpleTableTop",
 *     meshIds: ["purpleTableTopMesh"],
 *     isObject: true // <---- Registers Entity by ID on viewer.scene.objects
 * });
 *
 * // Finalize the SceneModel.
 *
 * SceneModel.finalize();
 *
 * // Find BigModelNodes by their model and object IDs
 *
 * // Get the whole table model
 * const table = viewer.scene.models["table"];
 *
 * // Get some leg objects
 * const redLeg = viewer.scene.objects["redLeg"];
 * const greenLeg = viewer.scene.objects["greenLeg"];
 * const blueLeg = viewer.scene.objects["blueLeg"];
 * ````
 *
 * ## Classifying with Metadata
 *
 * In the previous examples, we used ````SceneModel```` to build
 * two versions of the same table model, to demonstrate geometry batching and geometry instancing.
 *
 * We'll now classify our {@link Entity}s with metadata. This metadata
 * will work the same for both our examples, since they create the exact same structure of {@link Entity}s
 * to represent their models and objects. The abstract Entity type is, after all, intended to provide an abstract interface through which differently-implemented scene content can be accessed uniformly.
 *
 * To create the metadata, we'll create a {@link MetaModel} for our model,
 * with a {@link MetaObject} for each of it's objects. The MetaModel and MetaObjects
 * get the same IDs as the {@link Entity}s that represent their model and objects within our scene.
 *
 * ```` javascript
 * const furnitureMetaModel = viewer.metaScene.createMetaModel("furniture", {         // Creates a MetaModel in the MetaScene
 *
 *      "projectId": "myTableProject",
 *      "revisionId": "V1.0",
 *
 *      "metaObjects": [
 *          {                               // Creates a MetaObject in the MetaModel
 *              "id": "table",
 *              "name": "Table",            // Same ID as an object Entity
 *              "type": "furniture",        // Arbitrary type, could be IFC type
 *              "properties": {             // Arbitrary properties, could be IfcPropertySet
 *                  "cost": "200"
 *              }
 *          },
 *          {
 *              "id": "redLeg",
 *              "name": "Red table Leg",
 *              "type": "leg",
 *              "parent": "table",           // References first MetaObject as parent
 *              "properties": {
 *                  "material": "wood"
 *              }
 *          },
 *          {
 *              "id": "greenLeg",           // Node with corresponding id does not need to exist
 *              "name": "Green table leg",  // and MetaObject does not need to exist for Node with an id
 *              "type": "leg",
 *              "parent": "table",
 *              "properties": {
 *                  "material": "wood"
 *              }
 *          },
 *          {
 *              "id": "blueLeg",
 *              "name": "Blue table leg",
 *              "type": "leg",
 *              "parent": "table",
 *              "properties": {
 *                  "material": "wood"
 *              }
 *          },
 *          {
 *              "id": "yellowLeg",
 *              "name": "Yellow table leg",
 *              "type": "leg",
 *              "parent": "table",
 *              "properties": {
 *                  "material": "wood"
 *              }
 *          },
 *          {
 *              "id": "tableTop",
 *              "name": "Purple table top",
 *              "type": "surface",
 *              "parent": "table",
 *              "properties": {
 *                  "material": "formica",
 *                  "width": "60",
 *                  "depth": "60",
 *                  "thickness": "5"
 *              }
 *          }
 *      ]
 *  });
 * ````
 *
 * ## Querying Metadata
 *
 * Having created and classified our model (either the instancing or batching example), we can now find the {@link MetaModel}
 * and {@link MetaObject}s using the IDs of their
 * corresponding {@link Entity}s.
 *
 * ````JavaScript
 * const furnitureMetaModel = scene.metaScene.metaModels["furniture"];
 *
 * const redLegMetaObject = scene.metaScene.metaObjects["redLeg"];
 * ````
 *
 * In the snippet below, we'll log metadata on each {@link Entity} we click on:
 *
 * ````JavaScript
 * viewer.scene.input.on("mouseclicked", function (coords) {
 *
 *      const hit = viewer.scene.pick({
 *          canvasPos: coords
 *      });
 *
 *      if (hit) {
 *          const entity = hit.entity;
 *          const metaObject = viewer.metaScene.metaObjects[entity.id];
 *          if (metaObject) {
 *              console.log(JSON.stringify(metaObject.getJSON(), null, "\t"));
 *          }
 *      }
 *  });
 * ````
 *
 * ## Metadata Structure
 *
 * The {@link MetaModel}
 * organizes its {@link MetaObject}s in
 * a tree that describes their structural composition:
 *
 * ````JavaScript
 * // Get metadata on the root object
 * const tableMetaObject = furnitureMetaModel.rootMetaObject;
 *
 * // Get metadata on the leg objects
 * const redLegMetaObject = tableMetaObject.children[0];
 * const greenLegMetaObject = tableMetaObject.children[1];
 * const blueLegMetaObject = tableMetaObject.children[2];
 * const yellowLegMetaObject = tableMetaObject.children[3];
 * ````
 *
 * Given an {@link Entity}, we can find the object or model of which it is a part, or the objects that comprise it. We can also generate UI
 * components from the metadata, such as the tree view demonstrated in [this demo](https://xeokit.github.io/xeokit-sdk/examples/index.html#BIMOffline_glTF_OTCConferenceCenter).
 *
 * This hierarchy allows us to express the hierarchical structure of a model while representing it in
 * various ways in the 3D scene (such as with ````SceneModel````, which
 * has a non-hierarchical scene representation).
 *
 * Note also that a {@link MetaObject} does not need to have a corresponding
 * {@link Entity} and vice-versa.
 *
 * # RTC Coordinates for Double Precision
 *
 * ````SceneModel```` can emulate 64-bit precision on GPUs using relative-to-center (RTC) coordinates.
 *
 * Consider a model that contains many small objects, but with such large spatial extents that 32 bits of GPU precision (accurate to ~7 digits) will not be sufficient to render all of the the objects without jittering.
 *
 * To prevent jittering, we could spatially subdivide the objects into "tiles". Each tile would have a center position, and the positions of the objects within the tile would be relative to that center ("RTC coordinates").
 *
 * While the center positions of the tiles would be 64-bit values, the object positions only need to be 32-bit.
 *
 * Internally, when rendering an object with RTC coordinates, xeokit first temporarily translates the camera viewing matrix by the object's tile's RTC center, on the CPU, using 64-bit math.
 *
 * Then xeokit loads the viewing matrix into its WebGL shaders, where math happens at 32-bit precision. Within the shaders, the matrix is effectively down-cast to 32-bit precision, and the object's 32-bit vertex positions are transformed by the matrix.
 *
 * We see no jittering, because with RTC a detectable loss of GPU accuracy only starts happening to objects as they become very distant from the camera viewpoint, at which point they are too small to be discernible anyway.
 *
 * ## RTC Coordinates with Geometry Instancing
 *
 * To use RTC with ````SceneModel```` geometry instancing, we specify an RTC center for the geometry via its ````origin```` parameter. Then ````SceneModel```` assumes that all meshes that instance that geometry are within the same RTC coordinate system, ie. the meshes ````position```` and ````rotation```` properties are assumed to be relative to the geometry's ````origin````.
 *
 * For simplicity, our example's meshes all instance the same geometry. Therefore, our example model has only one RTC center.
 *
 * Note that the axis-aligned World-space boundary (AABB) of our model is ````[ -6, -9, -6, 1000000006, -2.5, 1000000006]````.
 *
 * [![](http://xeokit.io/img/docs/sceneGraph.png)](https://xeokit.github.io/xeokit-sdk/examples/index.html#sceneRepresentation_SceneModel_batching)
 *
 * ````javascript
 * const origin = [100000000, 0, 100000000];
 *
 * sceneModel.createGeometry({
 *     id: "box",
 *     primitive: "triangles",
 *     positions: [ 1, 1, 1, -1, 1, 1, -1, -1, 1, 1, -1, 1 ... ],
 *     normals: [ 0, 0, 1, 0, 0, 1, 0, 0, 1, 0, 0, 1, ... ],
 *     indices: [ 0, 1, 2, 0, 2, 3, 4, 5, 6, 4, 6, 7, ... ],
 * });
 *
 * sceneModel.createMesh({
 *     id: "leg1",
 *     geometryId: "box",
 *     position: [-4, -6, -4],
 *     scale: [1, 3, 1],
 *     rotation: [0, 0, 0],
 *     color: [1, 0.3, 0.3],
 *     origin: origin
 * });
 *
 * sceneModel.createEntity({
 *     meshIds: ["leg1"],
 *     isObject: true
 * });
 *
 * sceneModel.createMesh({
 *     id: "leg2",
 *     geometryId: "box",
 *     position: [4, -6, -4],
 *     scale: [1, 3, 1],
 *     rotation: [0, 0, 0],
 *     color: [0.3, 1.0, 0.3],
 *     origin: origin
 * });
 *
 * sceneModel.createEntity({
 *     meshIds: ["leg2"],
 *     isObject: true
 * });
 *
 * sceneModel.createMesh({
 *     id: "leg3",
 *     geometryId: "box",
 *     position: [4, -6, 4],
 *     scale: [1, 3, 1],
 *     rotation: [0, 0, 0],
 *     color: [0.3, 0.3, 1.0],
 *     origin: origin
 * });
 *
 * sceneModel.createEntity({
 *     meshIds: ["leg3"],
 *     isObject: true
 * });
 *
 * sceneModel.createMesh({
 *     id: "leg4",
 *     geometryId: "box",
 *     position: [-4, -6, 4],
 *     scale: [1, 3, 1],
 *     rotation: [0, 0, 0],
 *     color: [1.0, 1.0, 0.0],
 *     origin: origin
 * });
 *
 * sceneModel.createEntity({
 *     meshIds: ["leg4"],
 *     isObject: true
 * });
 *
 * sceneModel.createMesh({
 *     id: "top",
 *     geometryId: "box",
 *     position: [0, -3, 0],
 *     scale: [6, 0.5, 6],
 *     rotation: [0, 0, 0],
 *     color: [1.0, 0.3, 1.0],
 *     origin: origin
 * });
 *
 * sceneModel.createEntity({
 *     meshIds: ["top"],
 *     isObject: true
 * });
 * ````
 *
 * ## RTC Coordinates with Geometry Batching
 *
 * To use RTC with ````SceneModel```` geometry batching, we specify an RTC center (````origin````) for each mesh. For performance, we try to have as many meshes share the same value for ````origin```` as possible. Each mesh's ````positions````, ````position```` and ````rotation```` properties are assumed to be relative to ````origin````.
 *
 * For simplicity, the meshes in our example all share the same RTC center.
 *
 * The axis-aligned World-space boundary (AABB) of our model is ````[ -6, -9, -6, 1000000006, -2.5, 1000000006]````.
 *
 * [![](http://xeokit.io/img/docs/sceneGraph.png)](https://xeokit.github.io/xeokit-sdk/examples/index.html#sceneRepresentation_SceneModel_batching)
 *
 * ````javascript
 * const origin = [100000000, 0, 100000000];
 *
 * sceneModel.createMesh({
 *     id: "leg1",
 *     origin: origin, // This mesh's positions and transforms are relative to the RTC center
 *     primitive: "triangles",
 *     positions: [ 1, 1, 1, -1, 1, 1, -1, -1, 1, 1, -1, 1 ... ],
 *     normals: [ 0, 0, 1, 0, 0, 1, 0, 0, 1, 0, 0, 1, ... ],
 *     indices: [ 0, 1, 2, 0, 2, 3, 4, 5, 6, 4, 6, 7, ... ],
 *     position: [-4, -6, -4],
 *     scale: [1, 3, 1],
 *     rotation: [0, 0, 0],
 *     color: [1, 0.3, 0.3]
 * });
 *
 * sceneModel.createEntity({
 *     meshIds: ["leg1"],
 *     isObject: true
 * });
 *
 * sceneModel.createMesh({
 *     id: "leg2",
 *     origin: origin, // This mesh's positions and transforms are relative to the RTC center
 *     primitive: "triangles",
 *     positions: [ 1, 1, 1, -1, 1, 1, -1, -1, 1, 1, -1, 1 ... ],
 *     normals: [ 0, 0, 1, 0, 0, 1, 0, 0, 1, 0, 0, 1, ... ],
 *     indices: [ 0, 1, 2, 0, 2, 3, 4, 5, 6, 4, 6, 7, ... ],
 *     position: [4, -6, -4],
 *     scale: [1, 3, 1],
 *     rotation: [0, 0, 0],
 *     color: [0.3, 1.0, 0.3]
 * });
 *
 * sceneModel.createEntity({
 *     meshIds: ["leg2"],
 *     isObject: true
 * });
 *
 * sceneModel.createMesh({
 *     id: "leg3",
 *     origin: origin, // This mesh's positions and transforms are relative to the RTC center
 *     primitive: "triangles",
 *     positions: [ 1, 1, 1, -1, 1, 1, -1, -1, 1, 1, -1, 1 ... ],
 *     normals: [ 0, 0, 1, 0, 0, 1, 0, 0, 1, 0, 0, 1, ... ],
 *     indices: [ 0, 1, 2, 0, 2, 3, 4, 5, 6, 4, 6, 7, ... ],
 *     position: [4, -6, 4],
 *     scale: [1, 3, 1],
 *     rotation: [0, 0, 0],
 *     color: [0.3, 0.3, 1.0]
 * });
 *
 * sceneModel.createEntity({
 *     meshIds: ["leg3"],
 *     isObject: true
 * });
 *
 * sceneModel.createMesh({
 *     id: "leg4",
 *     origin: origin, // This mesh's positions and transforms are relative to the RTC center
 *     primitive: "triangles",
 *     positions: [ 1, 1, 1, -1, 1, 1, -1, -1, 1, 1, -1, 1 ... ],
 *     normals: [ 0, 0, 1, 0, 0, 1, 0, 0, 1, 0, 0, 1, ... ],
 *     indices: [ 0, 1, 2, 0, 2, 3, 4, 5, 6, 4, 6, 7, ... ],
 *     position: [-4, -6, 4],
 *     scale: [1, 3, 1],
 *     rotation: [0, 0, 0],
 *     color: [1.0, 1.0, 0.0]
 * });
 *
 * sceneModel.createEntity({
 *     meshIds: ["leg4"],
 *     isObject: true
 * });
 *
 * sceneModel.createMesh({
 *     id: "top",
 *     origin: origin, // This mesh's positions and transforms are relative to the RTC center
 *     primitive: "triangles",
 *     positions: [ 1, 1, 1, -1, 1, 1, -1, -1, 1, 1, -1, 1 ... ],
 *     normals: [ 0, 0, 1, 0, 0, 1, 0, 0, 1, 0, 0, 1, ... ],
 *     indices: [ 0, 1, 2, 0, 2, 3, 4, 5, 6, 4, 6, 7, ... ],
 *     position: [0, -3, 0],
 *     scale: [6, 0.5, 6],
 *     rotation: [0, 0, 0],
 *     color: [1.0, 0.3, 1.0]
 * });
 *
 * sceneModel.createEntity({
 *     meshIds: ["top"],
 *     isObject: true
 * });
 * ````
 *
 * ## Positioning at World-space coordinates
 *
 * To position a SceneModel at given double-precision World coordinates, we can
 * configure the ````origin```` of the SceneModel itself. The ````origin```` is a double-precision
 * 3D World-space position at which the SceneModel will be located.
 *
 * Note that ````position```` is a single-precision offset relative to ````origin````.
 *
 * ````javascript
 * const origin = [100000000, 0, 100000000];
 *
 * const sceneModel = new SceneModel(viewer.scene, {
 *     id: "table",
 *     isModel: true,
 *     origin: origin, // Everything in this SceneModel is relative to this RTC center
 *     position: [0, 0, 0],
 *     scale: [1, 1, 1],
 *     rotation: [0, 0, 0]
 * });
 *
 * sceneModel.createGeometry({
 *     id: "box",
 *     primitive: "triangles",
 *     positions: [ 1, 1, 1, -1, 1, 1, -1, -1, 1, 1, -1, 1 ... ],
 *     normals: [ 0, 0, 1, 0, 0, 1, 0, 0, 1, 0, 0, 1, ... ],
 *     indices: [ 0, 1, 2, 0, 2, 3, 4, 5, 6, 4, 6, 7, ... ],
 * });
 *
 * sceneModel.createMesh({
 *     id: "leg1",
 *     geometryId: "box",
 *     position: [-4, -6, -4],
 *     scale: [1, 3, 1],
 *     rotation: [0, 0, 0],
 *     color: [1, 0.3, 0.3]
 * });
 *
 * sceneModel.createEntity({
 *     meshIds: ["leg1"],
 *     isObject: true
 * });
 *
 * sceneModel.createMesh({
 *     id: "leg2",
 *     geometryId: "box",
 *     position: [4, -6, -4],
 *     scale: [1, 3, 1],
 *     rotation: [0, 0, 0],
 *     color: [0.3, 1.0, 0.3]
 * });
 *
 * sceneModel.createEntity({
 *     meshIds: ["leg2"],
 *     isObject: true
 * });
 *
 * sceneModel.createMesh({
 *     id: "leg3",
 *     geometryId: "box",
 *     position: [4, -6, 4],
 *     scale: [1, 3, 1],
 *     rotation: [0, 0, 0],
 *     color: [0.3, 0.3, 1.0]
 * });
 *
 * sceneModel.createEntity({
 *     meshIds: ["leg3"],
 *     isObject: true
 * });
 *
 * sceneModel.createMesh({
 *     id: "leg4",
 *     geometryId: "box",
 *     position: [-4, -6, 4],
 *     scale: [1, 3, 1],
 *     rotation: [0, 0, 0],
 *     color: [1.0, 1.0, 0.0]
 * });
 *
 * sceneModel.createEntity({
 *     meshIds: ["leg4"],
 *     isObject: true
 * });
 *
 * sceneModel.createMesh({
 *     id: "top",
 *     geometryId: "box",
 *     position: [0, -3, 0],
 *     scale: [6, 0.5, 6],
 *     rotation: [0, 0, 0],
 *     color: [1.0, 0.3, 1.0]
 * });
 *
 * sceneModel.createEntity({
 *     meshIds: ["top"],
 *     isObject: true
 * });
 * ````
 *
 * # Textures
 *
 * ## Loading KTX2 Texture Files into a SceneModel
 *
 * A {@link SceneModel} that is configured with a {@link KTX2TextureTranscoder} will
 * allow us to load textures into it from KTX2 buffers or files.
 *
 * In the example below, we'll create a {@link Viewer}, containing a {@link SceneModel} configured with a
 * {@link KTX2TextureTranscoder}. We'll then programmatically create a simple object within the SceneModel, consisting of
 * a single mesh with a texture loaded from a KTX2 file, which our SceneModel internally transcodes, using
 * its {@link KTX2TextureTranscoder}. Note how we configure our {@link KTX2TextureTranscoder} with a path to the Basis Universal
 * transcoder WASM module.
 *
 * ````javascript
 * const viewer = new Viewer({
 *     canvasId: "myCanvas",
 *     transparent: true
 * });
 *
 * viewer.scene.camera.eye = [-21.80, 4.01, 6.56];
 * viewer.scene.camera.look = [0, -5.75, 0];
 * viewer.scene.camera.up = [0.37, 0.91, -0.11];
 *
 * const textureTranscoder = new KTX2TextureTranscoder({
 *     viewer,
 *     transcoderPath: "https://cdn.jsdelivr.net/npm/@xeokit/xeokit-sdk/dist/basis/" // <------ Path to BasisU transcoder module
 * });
 *
 * const sceneModel = new SceneModel(viewer.scene, {
 *      id: "myModel",
 *      textureTranscoder // <<-------------------- Configure model with our transcoder
 *  });
 *
 * sceneModel.createTexture({
 *      id: "myColorTexture",
 *      src: "../assets/textures/compressed/sample_uastc_zstd.ktx2" // <<----- KTX2 texture asset
 * });
 *
 * sceneModel.createTexture({
 *      id: "myMetallicRoughnessTexture",
 *      src: "../assets/textures/alpha/crosshatchAlphaMap.jpg" // <<----- JPEG texture asset
 * });
 *
 * sceneModel.createTextureSet({
 *      id: "myTextureSet",
 *      colorTextureId: "myColorTexture",
 *      metallicRoughnessTextureId: "myMetallicRoughnessTexture"
 *  });
 *
 * sceneModel.createMesh({
 *      id: "myMesh",
 *      textureSetId: "myTextureSet",
 *      primitive: "triangles",
 *      positions: [1, 1, 1, ...],
 *      normals: [0, 0, 1, 0, ...],
 *      uv: [1, 0, 0, ...],
 *      indices: [0, 1, 2, ...],
 *  });
 *
 * sceneModel.createEntity({
 *      id: "myEntity",
 *      meshIds: ["myMesh"]
 *  });
 *
 * sceneModel.finalize();
 * ````
 *
 * ## Loading KTX2 Textures from ArrayBuffers into a SceneModel
 *
 * A SceneModel that is configured with a {@link KTX2TextureTranscoder} will allow us to load textures into
 * it from KTX2 ArrayBuffers.
 *
 * In the example below, we'll create a {@link Viewer}, containing a {@link SceneModel} configured with a
 * {@link KTX2TextureTranscoder}. We'll then programmatically create a simple object within the SceneModel, consisting of
 * a single mesh with a texture loaded from a KTX2 ArrayBuffer, which our SceneModel internally transcodes, using
 * its {@link KTX2TextureTranscoder}.
 *
 * ````javascript
 * const viewer = new Viewer({
 *     canvasId: "myCanvas",
 *     transparent: true
 * });
 *
 * viewer.scene.camera.eye = [-21.80, 4.01, 6.56];
 * viewer.scene.camera.look = [0, -5.75, 0];
 * viewer.scene.camera.up = [0.37, 0.91, -0.11];
 *
 * const textureTranscoder = new KTX2TextureTranscoder({
 *     viewer,
 *     transcoderPath: "https://cdn.jsdelivr.net/npm/@xeokit/xeokit-sdk/dist/basis/" // <------ Path to BasisU transcoder module
 * });
 *
 * const sceneModel = new SceneModel(viewer.scene, {
 *      id: "myModel",
 *      textureTranscoder // <<-------------------- Configure model with our transcoder
 * });
 *
 * utils.loadArraybuffer("../assets/textures/compressed/sample_uastc_zstd.ktx2",(arrayBuffer) => {
 *
 *     sceneModel.createTexture({
 *         id: "myColorTexture",
 *         buffers: [arrayBuffer] // <<----- KTX2 texture asset
 *     });
 *
 *     sceneModel.createTexture({
 *         id: "myMetallicRoughnessTexture",
 *         src: "../assets/textures/alpha/crosshatchAlphaMap.jpg" // <<----- JPEG texture asset
 *     });
 *
 *     sceneModel.createTextureSet({
 *        id: "myTextureSet",
 *        colorTextureId: "myColorTexture",
 *        metallicRoughnessTextureId: "myMetallicRoughnessTexture"
 *     });
 *
 *     sceneModel.createMesh({
 *          id: "myMesh",
 *          textureSetId: "myTextureSet",
 *          primitive: "triangles",
 *          positions: [1, 1, 1, ...],
 *          normals: [0, 0, 1, 0, ...],
 *          uv: [1, 0, 0, ...],
 *          indices: [0, 1, 2, ...],
 *     });
 *
 *     sceneModel.createEntity({
 *         id: "myEntity",
 *         meshIds: ["myMesh"]
 *     });
 *
 *     sceneModel.finalize();
 * });
 * ````
 *
 * @implements {Entity}
 */
export class SceneModel extends Component {

    /**
     * @constructor
     * @param {Component} owner Owner component. When destroyed, the owner will destroy this component as well.
     * @param {*} [cfg] Configs
     * @param {String} [cfg.id] Optional ID, unique among all components in the parent scene, generated automatically when omitted.
     * @param {Boolean} [cfg.isModel] Specify ````true```` if this SceneModel represents a model, in which case the SceneModel will be registered by {@link SceneModel#id} in {@link Scene#models} and may also have a corresponding {@link MetaModel} with matching {@link MetaModel#id}, registered by that ID in {@link MetaScene#metaModels}.
     * @param {Number[]} [cfg.origin=[0,0,0]] World-space double-precision 3D origin.
     * @param {Number[]} [cfg.position=[0,0,0]] Local, single-precision 3D position, relative to the origin parameter.
     * @param {Number[]} [cfg.scale=[1,1,1]] Local scale.
     * @param {Number[]} [cfg.rotation=[0,0,0]] Local rotation, as Euler angles given in degrees, for each of the X, Y and Z axis.
     * @param {Number[]} [cfg.matrix=[1,0,0,0,0,1,0,0,0,0,1,0,0,0,0,1] Local modelling transform matrix. Overrides the position, scale and rotation parameters.
     * @param {Boolean} [cfg.visible=true] Indicates if the SceneModel is initially visible.
     * @param {Boolean} [cfg.culled=false] Indicates if the SceneModel is initially culled from view.
     * @param {Boolean} [cfg.pickable=true] Indicates if the SceneModel is initially pickable.
     * @param {Boolean} [cfg.clippable=true] Indicates if the SceneModel is initially clippable.
     * @param {Boolean} [cfg.collidable=true] Indicates if the SceneModel is initially included in boundary calculations.
     * @param {Boolean} [cfg.xrayed=false] Indicates if the SceneModel is initially xrayed.
     * @param {Boolean} [cfg.highlighted=false] Indicates if the SceneModel is initially highlighted.
     * @param {Boolean} [cfg.selected=false] Indicates if the SceneModel is initially selected.
     * @param {Boolean} [cfg.edges=false] Indicates if the SceneModel's edges are initially emphasized.
     * @param {Number[]} [cfg.colorize=[1.0,1.0,1.0]] SceneModel's initial RGB colorize color, multiplies by the rendered fragment colors.
     * @param {Number} [cfg.opacity=1.0] SceneModel's initial opacity factor, multiplies by the rendered fragment alpha.
     * @param {Number} [cfg.backfaces=false] When we set this ````true````, then we force rendering of backfaces for this SceneModel. When
     * we leave this ````false````, then we allow the Viewer to decide when to render backfaces. In that case, the
     * Viewer will hide backfaces on watertight meshes, show backfaces on open meshes, and always show backfaces on meshes when we slice them open with {@link SectionPlane}s.
     * @param {Boolean} [cfg.saoEnabled=true] Indicates if Scalable Ambient Obscurance (SAO) will apply to this SceneModel. SAO is configured by the Scene's {@link SAO} component.
     * @param {Boolean} [cfg.pbrEnabled=true] Indicates if physically-based rendering (PBR) will apply to the SceneModel when {@link Scene#pbrEnabled} is ````true````.
     * @param {Boolean} [cfg.colorTextureEnabled=true] Indicates if base color textures will be rendered for the SceneModel when {@link Scene#colorTextureEnabled} is ````true````.
     * @param {Number} [cfg.edgeThreshold=10] When xraying, highlighting, selecting or edging, this is the threshold angle between normals of adjacent triangles, below which their shared wireframe edge is not drawn.
     * @param {Number} [cfg.maxGeometryBatchSize=50000000] Maximum geometry batch size, as number of vertices. This is optionally supplied
     * to limit the size of the batched geometry arrays that SceneModel internally creates for batched geometries.
     * A lower value means less heap allocation/de-allocation while creating/loading batched geometries, but more draw calls and
     * slower rendering speed. A high value means larger heap allocation/de-allocation while creating/loading, but less draw calls
     * and faster rendering speed. It's recommended to keep this somewhere roughly between ````50000```` and ````50000000```.
     * @param {TextureTranscoder} [cfg.textureTranscoder] Transcoder that will be used internally by {@link SceneModel#createTexture}
     * to convert transcoded texture data. Only required when we'll be providing transcoded data
     * to {@link SceneModel#createTexture}. We assume that all transcoded texture data added to a  ````SceneModel````
     * will then in a format supported by this transcoder.
     * @param {Boolean} [cfg.dtxEnabled=true] When ````true```` (default) use data textures (DTX), where appropriate, to
     * represent the returned model. Set false to always use vertex buffer objects (VBOs). Note that DTX is only applicable
     * to non-textured triangle meshes, and that VBOs are always used for meshes that have textures, line segments, or point
     * primitives. Only works while {@link DTX#enabled} is also ````true````.
     * @param {Number} [cfg.renderOrder=0] Specifies the rendering order for this SceneModel. This is used to control the order in which
     * SceneModels are drawn when they have transparent objects, to give control over the order in which those objects are blended within the transparent
     * render pass.
     */
    constructor(owner, cfg = {}) {

        super(owner, cfg);

        this.renderOrder = cfg.renderOrder || 0;

        this._dtxEnabled = this.scene.dtxEnabled && (cfg.dtxEnabled !== false);

        this._enableVertexWelding = false; // Not needed for most objects, and very expensive, so disabled
        this._enableIndexBucketing = false; // Until fixed: https://github.com/xeokit/xeokit-sdk/issues/1204

        this._textureTranscoder = cfg.textureTranscoder || getKTX2TextureTranscoder(this.scene.viewer);

        this._maxGeometryBatchSize = cfg.maxGeometryBatchSize ?? 5000000;

        this._aabb = math.collapseAABB3();
        this._aabbDirty = true;

        this._quantizationRanges = {};

        this._vboLayers = {};
        this._dtxLayers = {};

        this._meshList = [];

        this.layerList = []; // For GL state efficiency when drawing, InstancingLayers are in first part, BatchingLayers are in second
        this._layersToFinalize = [];

        this._entityList = [];
        this._entitiesToFinalize = [];

        this._geometries = {};
        this._dtxBuckets = {}; // Geometries with optimizations used for data texture representation
        this._textures = {};
        this._textureSets = {};
        this._transforms = {};
        this._meshes = {};
        this._unusedMeshes = {};
        this._entities = {};

        /** @private **/
        this.renderFlags = new RenderFlags();

        /**
         * @private
         */
        this.numGeometries = 0; // Number of geometries created with createGeometry()

        // These counts are used to avoid unnecessary render passes
        // They are incremented or decremented exclusively by BatchingLayer and InstancingLayer

        /**
         * @private
         */
        this.numPortions = 0;

        /**
         * @private
         */
        this.numVisibleLayerPortions = 0;

        /**
         * @private
         */
        this.numTransparentLayerPortions = 0;

        /**
         * @private
         */
        this.numXRayedLayerPortions = 0;

        /**
         * @private
         */
        this.numHighlightedLayerPortions = 0;

        /**
         * @private
         */
        this.numSelectedLayerPortions = 0;

        /**
         * @private
         */
        this.numEdgesLayerPortions = 0;

        /**
         * @private
         */
        this.numPickableLayerPortions = 0;

        /**
         * @private
         */
        this.numClippableLayerPortions = 0;

        /**
         * @private
         */
        this.numCulledLayerPortions = 0;

        this.numEntities = 0;
        this._numTriangles = 0;
        this._numLines = 0;
        this._numPoints = 0;
        this._layersFinalized = false;

        this._edgeThreshold = cfg.edgeThreshold || 10;

        // Build static matrix

        this._origin = math.vec3(cfg.origin || [0, 0, 0]);
        this._position = math.vec3(cfg.position || [0, 0, 0]);
        this._rotation = math.vec3(cfg.rotation || [0, 0, 0]);
        this._quaternion = math.vec4(cfg.quaternion || [0, 0, 0, 1]);
        this._conjugateQuaternion = math.vec4(cfg.quaternion || [0, 0, 0, 1]);

        if (cfg.rotation) {
            math.eulerToQuaternion(this._rotation, "XYZ", this._quaternion);
        }
        this._scale = math.vec3(cfg.scale || [1, 1, 1]);

        this._worldRotationMatrix = math.mat4();
        this._worldRotationMatrixConjugate = math.mat4();
        this._matrix = math.mat4();
        this._matrixDirty = true;

        this._rebuildMatrices();

        this._worldNormalMatrix = math.mat4();
        math.inverseMat4(this._matrix, this._worldNormalMatrix);
        math.transposeMat4(this._worldNormalMatrix);

        if (cfg.matrix || cfg.position || cfg.rotation || cfg.scale || cfg.quaternion) {
            this._viewMatrix = math.mat4();
            this._viewNormalMatrix = math.mat4();
            this._viewMatrixDirty = true;
            this._matrixNonIdentity = true;
        }

        this._opacity = 1.0;
        this._colorize = [1, 1, 1];

        this._saoEnabled = (cfg.saoEnabled !== false);
        this._pbrEnabled = (cfg.pbrEnabled !== false);
        this._colorTextureEnabled = (cfg.colorTextureEnabled !== false);

        this._isModel = cfg.isModel;
        if (this._isModel) {
            this.scene._registerModel(this);
        }

        this._onCameraViewMatrix = this.scene.camera.on("matrix", () => {
            this._viewMatrixDirty = true;
        });

        this._meshesWithDirtyMatrices = [];
        this._numMeshesWithDirtyMatrices = 0;

        this._onTick = this.scene.on("tick", () => {
            while (this._numMeshesWithDirtyMatrices > 0) {
                this._meshesWithDirtyMatrices[--this._numMeshesWithDirtyMatrices]._updateMatrix();
            }
        });

        // Every SceneModelMesh gets at least the default TextureSet,
        // which contains empty default textures filled with color
        const defineTex = (texId, preloadColor) => {
            return this._textures[texId] = new SceneModelTexture({
                id: texId,
                texture: new Texture2D({
                    gl: this.scene.canvas.gl,
                    preloadColor: preloadColor
                })
            });
        };

        this._textureSets[DEFAULT_TEXTURE_SET_ID] = new SceneModelTextureSet({
            id: DEFAULT_TEXTURE_SET_ID,
            colorTexture:             defineTex(DEFAULT_COLOR_TEXTURE_ID,       [1, 1, 1, 1]), // [r, g, b, a]}),
            metallicRoughnessTexture: defineTex(DEFAULT_METAL_ROUGH_TEXTURE_ID, [0, 1, 1, 1]), // [_, roughness, metalness, _],
            normalsTexture:           defineTex(DEFAULT_NORMALS_TEXTURE_ID,     [0, 0, 0, 0]), // [x, y, z, _] - these must be zeros
            emissiveTexture:          defineTex(DEFAULT_EMISSIVE_TEXTURE_ID,    [0, 0, 0, 1]), // [x, y, z, _]
            occlusionTexture:         defineTex(DEFAULT_OCCLUSION_TEXTURE_ID,   [1, 1, 1, 1])  // [x, y, z, _]
        });

        this.visible = cfg.visible;
        this.culled = cfg.culled;
        this.pickable = cfg.pickable;
        this.clippable = cfg.clippable;
        this.collidable = cfg.collidable;
        this.castsShadow = cfg.castsShadow;
        this.receivesShadow = cfg.receivesShadow;
        this.xrayed = cfg.xrayed;
        this.highlighted = cfg.highlighted;
        this.selected = cfg.selected;
        this.edges = cfg.edges;
        this.colorize = cfg.colorize;
        this.opacity = cfg.opacity;
        this.backfaces = cfg.backfaces;
    }

    _meshMatrixDirty(mesh) {
        this._meshesWithDirtyMatrices[this._numMeshesWithDirtyMatrices++] = mesh;
    }

    //------------------------------------------------------------------------------------------------------------------
    // SceneModel members
    //------------------------------------------------------------------------------------------------------------------

    /**
     * Returns true to indicate that this Component is a SceneModel.
     * @type {Boolean}
     */
    get isPerformanceModel() {
        return true;
    }

    /**
     * The {@link SceneModelTransform}s in this SceneModel.
     *
     * Each {#link SceneModelTransform} is stored here against its {@link SceneModelTransform.id}.
     *
     * @returns {*|{}}
     */
    get transforms() {
        return this._transforms;
    }

    /**
     * The {@link SceneModelTexture}s in this SceneModel.
     *
     * * Each {@link SceneModelTexture} is created with {@link SceneModel.createTexture}.
     * * Each {@link SceneModelTexture} is stored here against its {@link SceneModelTexture.id}.
     *
     * @returns {*|{}}
     */
    get textures() {
        return this._textures;
    }

    /**
     * The {@link SceneModelTextureSet}s in this SceneModel.
     *
     * Each {@link SceneModelTextureSet} is stored here against its {@link SceneModelTextureSet.id}.
     *
     * @returns {*|{}}
     */
    get textureSets() {
        return this._textureSets;
    }

    /**
     * The {@link SceneModelMesh}es in this SceneModel.
     *
     * Each {@SceneModelMesh} is stored here against its {@link SceneModelMesh.id}.
     *
     * @returns {*|{}}
     */
    get meshes() {
        return this._meshes;
    }

    /**
     * The {@link SceneModelEntity}s in this SceneModel.
     *
     * Each {#link SceneModelEntity} in this SceneModel that represents an object is
     * stored here against its {@link SceneModelTransform.id}.
     *
     * @returns {*|{}}
     */
    get objects() {
        return this._entities;
    }

    /**
     * Gets the 3D World-space origin for this SceneModel.
     *
     * Each {@link SceneModelMesh.origin}, if supplied, is relative to this origin.
     *
     * Default value is ````[0,0,0]````.
     *
     * @type {Float64Array}
     */
    get origin() {
        return this._origin;
    }

    /**
     * Sets the SceneModel's local translation.
     *
     * Default value is ````[0,0,0]````.
     *
     * @type {Number[]}
     */
    set position(value) {
        this._position.set(value || [0, 0, 0]);
        this._setWorldMatrixDirty();
        this._sceneModelDirty();
        this.glRedraw();
    }

    /**
     * Gets the SceneModel's local translation.
     *
     * Default value is ````[0,0,0]````.
     *
     * @type {Number[]}
     */
    get position() {
        return this._position;
    }

    /**
     * Sets the SceneModel's local rotation, as Euler angles given in degrees, for each of the X, Y and Z axis.
     *
     * Default value is ````[0,0,0]````.
     *
     * @type {Number[]}
     */
    set rotation(value) {
        this._rotation.set(value || [0, 0, 0]);
        math.eulerToQuaternion(this._rotation, "XYZ", this._quaternion);
        this._setWorldMatrixDirty();
        this._sceneModelDirty();
        this.glRedraw();
    }

    /**
     * Gets the SceneModel's local rotation, as Euler angles given in degrees, for each of the X, Y and Z axis.
     *
     * Default value is ````[0,0,0]````.
     *
     * @type {Number[]}
     */
    get rotation() {
        return this._rotation;
    }

    /**
     * Sets the SceneModel's local rotation quaternion.
     *
     * Default value is ````[0,0,0,1]````.
     *
     * @type {Number[]}
     */
    set quaternion(value) {
        this._quaternion.set(value || [0, 0, 0, 1]);
        math.quaternionToEuler(this._quaternion, "XYZ", this._rotation);
        this._setWorldMatrixDirty();
        this._sceneModelDirty();
        this.glRedraw();
    }

    /**
     * Gets the SceneModel's local rotation quaternion.
     *
     * Default value is ````[0,0,0,1]````.
     *
     * @type {Number[]}
     */
    get quaternion() {
        return this._quaternion;
    }

    /**
     * Sets the SceneModel's local scale.
     *
     * Default value is ````[1,1,1]````.
     *
     * @type {Number[]}
     * @deprecated
     */
    set scale(value) {
        // NOP - deprecated
    }

    /**
     * Gets the SceneModel's local scale.
     *
     * Default value is ````[1,1,1]````.
     *
     * @type {Number[]}
     * @deprecated
     */
    get scale() {
        return this._scale;
    }

    /**
     * Sets the SceneModel's local modeling transform matrix.
     *
     * Default value is ````[1, 0, 0, 0, 0, 1, 0, 0, 0, 0, 1, 0, 0, 0, 0, 1]````.
     *
     * @type {Number[]}
     */
    set matrix(value) {
        this._matrix.set(value || DEFAULT_MATRIX);
        math.decomposeMat4(this._matrix, this._position, this._quaternion, this._scale);
        math.quaternionToEuler(this._quaternion, "XYZ", this._rotation);
        this._matrixDirty = false;
        this._setWorldMatrixDirty();
        this._sceneModelDirty();
        this.glRedraw();
    }

    /**
     * Gets the SceneModel's local modeling transform matrix.
     *
     * Default value is ````[1, 0, 0, 0, 0, 1, 0, 0, 0, 0, 1, 0, 0, 0, 0, 1]````.
     *
     * @type {Number[]}
     */
    get matrix() {
        this._rebuildMatrices();
        return this._matrix;
    }

    /**
     * Gets the SceneModel's local modeling rotation transform matrix.
     *
     * @type {Number[]}
     */
    get rotationMatrix() {
        this._rebuildMatrices();
        return this._worldRotationMatrix;
    }

    _rebuildMatrices() {
        if (this._matrixDirty) {
            math.quaternionToRotationMat4(this._quaternion, this._worldRotationMatrix);
            math.conjugateQuaternion(this._quaternion, this._conjugateQuaternion);
            math.quaternionToRotationMat4(this._conjugateQuaternion, this._worldRotationMatrixConjugate);
            math.scaleMat4v(this._scale, this._worldRotationMatrix);
            math.scaleMat4v(this._scale, this._worldRotationMatrixConjugate);
            this._matrix.set(this._worldRotationMatrix);
            math.translateMat4v(this._position, this._matrix);
            this._matrixDirty = false;
            this._viewMatrixDirty = true;
        }
    }

    /**
     * Gets the conjugate of the SceneModel's local modeling rotation transform matrix.
     *
     * This is used for RTC view matrix management in renderers.
     *
     * @type {Number[]}
     */
    get rotationMatrixConjugate() {
        this._rebuildMatrices();
        return this._worldRotationMatrixConjugate;
    }

    _setWorldMatrixDirty() {
        this._matrixDirty = true;
        this._aabbDirty = true;
    }

    _transformDirty() {
        this._matrixDirty = true;
        this._aabbDirty = true;
        this.scene._aabbDirty = true;
    }

    _sceneModelDirty() {
        this.scene._aabbDirty = true;
        this._aabbDirty = true;
        this.scene._aabbDirty = true;
        this._matrixDirty = true;
        for (let i = 0, len = this._entityList.length; i < len; i++) {
            this._entityList[i]._sceneModelDirty(); // Entities need to retransform their World AABBs by SceneModel's worldMatrix
        }
    }

    /**
     * Gets the SceneModel's World matrix.
     *
     * @property worldMatrix
     * @type {Number[]}
     */
    get worldMatrix() {
        return this.matrix;
    }

    /**
     * Gets the SceneModel's World normal matrix.
     *
     * @type {Number[]}
     */
    get worldNormalMatrix() {
        return this._worldNormalMatrix;
    }

    _rebuildViewMatrices() {
        this._rebuildMatrices();
        if (this._viewMatrixDirty) {
            math.mulMat4(this.scene.camera.viewMatrix, this._matrix, this._viewMatrix);
            math.inverseMat4(this._viewMatrix, this._viewNormalMatrix);
            math.transposeMat4(this._viewNormalMatrix);
            this._viewMatrixDirty = false;
        }
    }

    /**
     * Called by private renderers in ./lib, returns the view matrix with which to
     * render this SceneModel. The view matrix is the concatenation of the
     * Camera view matrix with the Performance model's world (modeling) matrix.
     *
     * @private
     */
    get viewMatrix() {
        if (!this._viewMatrix) {
            return this.scene.camera.viewMatrix;
        }
        this._rebuildViewMatrices();
        return this._viewMatrix;
    }

    /**
     * Called by private renderers in ./lib, returns the view normal matrix with which to render this SceneModel.
     *
     * @private
     */
    get viewNormalMatrix() {
        if (!this._viewNormalMatrix) {
            return this.scene.camera.viewNormalMatrix;
        }
        this._rebuildViewMatrices();
        return this._viewNormalMatrix;
    }

    /**
     * Sets if backfaces are rendered for this SceneModel.
     *
     * Default is ````false````.
     *
     * @type {Boolean}
     */
    get backfaces() {
        return this._backfaces;
    }

    /**
     * Sets if backfaces are rendered for this SceneModel.
     *
     * Default is ````false````.
     *
     * When we set this ````true````, then backfaces are always rendered for this SceneModel.
     *
     * When we set this ````false````, then we allow the Viewer to decide whether to render backfaces. In this case,
     * the Viewer will:
     *
     *  * hide backfaces on watertight meshes,
     *  * show backfaces on open meshes, and
     *  * always show backfaces on meshes when we slice them open with {@link SectionPlane}s.
     *
     * @type {Boolean}
     */
    set backfaces(backfaces) {
        backfaces = !!backfaces;
        this._backfaces = backfaces;
        this.glRedraw();
    }

    /**
     * Gets the list of {@link SceneModelEntity}s within this SceneModel.
     *
     * @returns {SceneModelEntity[]}
     */
    get entityList() {
        return this._entityList;
    }

    /**
     * Returns true to indicate that SceneModel is an {@link Entity}.
     * @type {Boolean}
     */
    get isEntity() {
        return true;
    }

    /**
     * Returns ````true```` if this SceneModel represents a model.
     *
     * When ````true```` the SceneModel will be registered by {@link SceneModel#id} in
     * {@link Scene#models} and may also have a {@link MetaObject} with matching {@link MetaObject#id}.
     *
     * @type {Boolean}
     */
    get isModel() {
        return this._isModel;
    }

    //------------------------------------------------------------------------------------------------------------------
    // SceneModel members
    //------------------------------------------------------------------------------------------------------------------

    /**
     * Returns ````false```` to indicate that SceneModel never represents an object.
     *
     * @type {Boolean}
     */
    get isObject() {
        return false;
    }

    /**
     * Gets the SceneModel's World-space 3D axis-aligned bounding box.
     *
     * Represented by a six-element Float64Array containing the min/max extents of the
     * axis-aligned volume, ie. ````[xmin, ymin,zmin,xmax,ymax, zmax]````.
     *
     * @type {Number[]}
     */
    get aabb() {
        if (this._aabbDirty) {
            math.collapseAABB3(this._aabb);
            for (let i = 0, len = this._entityList.length; i < len; i++) {
                math.expandAABB3(this._aabb, this._entityList[i].aabb);
            }
            this._aabbDirty = false;
        }
        return this._aabb;
    }

    /**
     * The approximate number of triangle primitives in this SceneModel.
     *
     * @type {Number}
     */
    get numTriangles() {
        return this._numTriangles;
    }

    //------------------------------------------------------------------------------------------------------------------
    // Entity members
    //------------------------------------------------------------------------------------------------------------------

    /**
     * The approximate number of line primitives in this SceneModel.
     *
     * @type {Number}
     */
    get numLines() {
        return this._numLines;
    }

    /**
     * The approximate number of point primitives in this SceneModel.
     *
     * @type {Number}
     */
    get numPoints() {
        return this._numPoints;
    }

    /**
     * Gets if any {@link SceneModelEntity}s in this SceneModel are visible.
     *
     * The SceneModel is only rendered when {@link SceneModel#visible} is ````true```` and {@link SceneModel#culled} is ````false````.
     *
     * @type {Boolean}
     */
    get visible() {
        return (this.numVisibleLayerPortions > 0);
    }

    /**
     * Sets if this SceneModel is visible.
     *
     * The SceneModel is only rendered when {@link SceneModel#visible} is ````true```` and {@link SceneModel#culled} is ````false````.
     **
     * @type {Boolean}
     */
    set visible(visible) {
        visible = visible !== false;
        this._visible = visible;
        for (let i = 0, len = this._entityList.length; i < len; i++) {
            this._entityList[i].visible = visible;
        }
        this.glRedraw();
    }

    /**
     * Gets if any {@link SceneModelEntity}s in this SceneModel are xrayed.
     *
     * @type {Boolean}
     */
    get xrayed() {
        return (this.numXRayedLayerPortions > 0);
    }

    /**
     * Sets if all {@link SceneModelEntity}s in this SceneModel are xrayed.
     *
     * @type {Boolean}
     */
    set xrayed(xrayed) {
        xrayed = !!xrayed;
        this._xrayed = xrayed;
        for (let i = 0, len = this._entityList.length; i < len; i++) {
            this._entityList[i].xrayed = xrayed;
        }
        this.glRedraw();
    }

    /**
     * Gets if any {@link SceneModelEntity}s in this SceneModel are highlighted.
     *
     * @type {Boolean}
     */
    get highlighted() {
        return (this.numHighlightedLayerPortions > 0);
    }

    /**
     * Sets if all {@link SceneModelEntity}s in this SceneModel are highlighted.
     *
     * @type {Boolean}
     */
    set highlighted(highlighted) {
        highlighted = !!highlighted;
        this._highlighted = highlighted;
        for (let i = 0, len = this._entityList.length; i < len; i++) {
            this._entityList[i].highlighted = highlighted;
        }
        this.glRedraw();
    }

    /**
     * Gets if any {@link SceneModelEntity}s in this SceneModel are selected.
     *
     * @type {Boolean}
     */
    get selected() {
        return (this.numSelectedLayerPortions > 0);
    }

    /**
     * Sets if all {@link SceneModelEntity}s in this SceneModel are selected.
     *
     * @type {Boolean}
     */
    set selected(selected) {
        selected = !!selected;
        this._selected = selected;
        for (let i = 0, len = this._entityList.length; i < len; i++) {
            this._entityList[i].selected = selected;
        }
        this.glRedraw();
    }

    /**
     * Gets if any {@link SceneModelEntity}s in this SceneModel have edges emphasised.
     *
     * @type {Boolean}
     */
    get edges() {
        return (this.numEdgesLayerPortions > 0);
    }

    /**
     * Sets if all {@link SceneModelEntity}s in this SceneModel have edges emphasised.
     *
     * @type {Boolean}
     */
    set edges(edges) {
        edges = !!edges;
        this._edges = edges;
        for (let i = 0, len = this._entityList.length; i < len; i++) {
            this._entityList[i].edges = edges;
        }
        this.glRedraw();
    }

    /**
     * Gets if this SceneModel is culled from view.
     *
     * The SceneModel is only rendered when {@link SceneModel#visible} is true and {@link SceneModel#culled} is false.
     *
     * @type {Boolean}
     */
    get culled() {
        return this._culled;
    }

    /**
     * Sets if this SceneModel is culled from view.
     *
     * The SceneModel is only rendered when {@link SceneModel#visible} is true and {@link SceneModel#culled} is false.
     *
     * @type {Boolean}
     */
    set culled(culled) {
        culled = !!culled;
        this._culled = culled;
        for (let i = 0, len = this._entityList.length; i < len; i++) {
            this._entityList[i].culled = culled;
        }
        this.glRedraw();
    }

    /**
     * Gets if {@link SceneModelEntity}s in this SceneModel are clippable.
     *
     * Clipping is done by the {@link SectionPlane}s in {@link Scene#sectionPlanes}.
     *
     * @type {Boolean}
     */
    get clippable() {
        return this._clippable;
    }

    /**
     * Sets if {@link SceneModelEntity}s in this SceneModel are clippable.
     *
     * Clipping is done by the {@link SectionPlane}s in {@link Scene#sectionPlanes}.
     *
     * @type {Boolean}
     */
    set clippable(clippable) {
        clippable = clippable !== false;
        this._clippable = clippable;
        for (let i = 0, len = this._entityList.length; i < len; i++) {
            this._entityList[i].clippable = clippable;
        }
        this.glRedraw();
    }

    /**
     * Gets if this SceneModel is collidable.
     *
     * @type {Boolean}
     */
    get collidable() {
        return this._collidable;
    }

    /**
     * Sets if {@link SceneModelEntity}s in this SceneModel are collidable.
     *
     * @type {Boolean}
     */
    set collidable(collidable) {
        collidable = collidable !== false;
        this._collidable = collidable;
        for (let i = 0, len = this._entityList.length; i < len; i++) {
            this._entityList[i].collidable = collidable;
        }
    }

    /**
     * Gets if this SceneModel is pickable.
     *
     * Picking is done via calls to {@link Scene#pick}.
     *
     * @type {Boolean}
     */
    get pickable() {
        return (this.numPickableLayerPortions > 0);
    }

    /**
     * Sets if {@link SceneModelEntity}s in this SceneModel are pickable.
     *
     * Picking is done via calls to {@link Scene#pick}.
     *
     * @type {Boolean}
     */
    set pickable(pickable) {
        pickable = pickable !== false;
        this._pickable = pickable;
        for (let i = 0, len = this._entityList.length; i < len; i++) {
            this._entityList[i].pickable = pickable;
        }
    }

    /**
     * Gets the RGB colorize color for this SceneModel.
     *
     * Each element of the color is in range ````[0..1]````.
     *
     * @type {Number[]}
     */
    get colorize() {
        return this._colorize;
    }

    /**
     * Sets the RGB colorize color for this SceneModel.
     *
     * Multiplies by rendered fragment colors.
     *
     * Each element of the color is in range ````[0..1]````.
     *
     * @type {Number[]}
     */
    set colorize(colorize) {
        this._colorize = colorize;
        for (let i = 0, len = this._entityList.length; i < len; i++) {
            this._entityList[i].colorize = colorize;
        }
    }

    /**
     * Gets this SceneModel's opacity factor.
     *
     * This is a factor in range ````[0..1]```` which multiplies by the rendered fragment alphas.
     *
     * @type {Number}
     */
    get opacity() {
        return this._opacity;
    }

    /**
     * Sets the opacity factor for this SceneModel.
     *
     * This is a factor in range ````[0..1]```` which multiplies by the rendered fragment alphas.
     *
     * @type {Number}
     */
    set opacity(opacity) {
        this._opacity = opacity;
        for (let i = 0, len = this._entityList.length; i < len; i++) {
            this._entityList[i].opacity = opacity;
        }
    }

    /**
     * Gets if this SceneModel casts a shadow.
     *
     * @type {Boolean}
     */
    get castsShadow() {
        return this._castsShadow;
    }

    /**
     * Sets if this SceneModel casts a shadow.
     *
     * @type {Boolean}
     */
    set castsShadow(castsShadow) {
        castsShadow = (castsShadow !== false);
        if (castsShadow !== this._castsShadow) {
            this._castsShadow = castsShadow;
            this.glRedraw();
        }
    }

    /**
     * Sets if this SceneModel can have shadow cast upon it.
     *
     * @type {Boolean}
     */
    get receivesShadow() {
        return this._receivesShadow;
    }

    /**
     * Sets if this SceneModel can have shadow cast upon it.
     *
     * @type {Boolean}
     */
    set receivesShadow(receivesShadow) {
        receivesShadow = (receivesShadow !== false);
        if (receivesShadow !== this._receivesShadow) {
            this._receivesShadow = receivesShadow;
            this.glRedraw();
        }
    }

    /**
     * Gets if Scalable Ambient Obscurance (SAO) will apply to this SceneModel.
     *
     * SAO is configured by the Scene's {@link SAO} component.
     *
     *  Only works when {@link SAO#enabled} is also true.
     *
     * @type {Boolean}
     */
    get saoEnabled() {
        return this._saoEnabled;
    }

    /**
     * Gets if physically-based rendering (PBR) is enabled for this SceneModel.
     *
     * Only works when {@link Scene#pbrEnabled} is also true.
     *
     * @type {Boolean}
     */
    get pbrEnabled() {
        return this._pbrEnabled;
    }

    /**
     * Gets if color textures are enabled for this SceneModel.
     *
     * Only works when {@link Scene#colorTextureEnabled} is also true.
     *
     * @type {Boolean}
     */
    get colorTextureEnabled() {
        return this._colorTextureEnabled;
    }

    /**
     * Returns true to indicate that SceneModel is implements {@link Drawable}.
     *
     * @type {Boolean}
     */
    get isDrawable() {
        return true;
    }

    /** @private */
    get isStateSortable() {
        return false
    }

    /**
     * Configures the appearance of xrayed {@link SceneModelEntity}s within this SceneModel.
     *
     * This is the {@link Scene#xrayMaterial}.
     *
     * @type {EmphasisMaterial}
     */
    get xrayMaterial() {
        return this.scene.xrayMaterial;
    }

    /**
     * Configures the appearance of highlighted {@link SceneModelEntity}s within this SceneModel.
     *
     * This is the {@link Scene#highlightMaterial}.
     *
     * @type {EmphasisMaterial}
     */
    get highlightMaterial() {
        return this.scene.highlightMaterial;
    }

    /**
     * Configures the appearance of selected {@link SceneModelEntity}s within this SceneModel.
     *
     * This is the {@link Scene#selectedMaterial}.
     *
     * @type {EmphasisMaterial}
     */
    get selectedMaterial() {
        return this.scene.selectedMaterial;
    }

    /**
     * Configures the appearance of edges of {@link SceneModelEntity}s within this SceneModel.
     *
     * This is the {@link Scene#edgeMaterial}.
     *
     * @type {EdgeMaterial}
     */
    get edgeMaterial() {
        return this.scene.edgeMaterial;
    }

    //------------------------------------------------------------------------------------------------------------------
    // Drawable members
    //------------------------------------------------------------------------------------------------------------------

    /**
     * Called by private renderers in ./lib, returns the picking view matrix with which to
     * ray-pick on this SceneModel.
     *
     * @private
     */
    getPickViewMatrix(pickViewMatrix) {
        if (!this._viewMatrix) {
            return pickViewMatrix;
        }
        return this._viewMatrix;
    }

    /**
     *
     * @param cfg
     */
    createQuantizationRange(cfg) {
        if (cfg.id === undefined || cfg.id === null) {
            this.error("[createQuantizationRange] Config missing: id");
            return;
        }
        if (cfg.aabb) {
            this.error("[createQuantizationRange] Config missing: aabb");
            return;
        }
        if (this._quantizationRanges[cfg.id]) {
            this.error("[createQuantizationRange] QuantizationRange already created: " + cfg.id);
            return;
        }
        this._quantizationRanges[cfg.id] = {
            id: cfg.id,
            aabb: cfg.aabb,
            matrix: createPositionsDecodeMatrix(cfg.aabb, math.mat4())
        }
    }

    _createDefaultIndices(numIndices) {
        const indices = [];
        for (let i = 0; i < numIndices; i++) {
            indices.push(i);
        }
        return indices;
    }

    /**
     * Creates a reusable geometry within this SceneModel.
     *
     * We can then supply the geometry ID to {@link SceneModel#createMesh} when we want to create meshes that
     * instance the geometry.
     *
     * @param {*} cfg Geometry properties.
     * @param {String|Number} cfg.id Mandatory ID for the geometry, to refer to with {@link SceneModel#createMesh}.
     * @param {String} cfg.primitive The primitive type. Accepted values are 'points', 'lines', 'triangles', 'solid' and 'surface'.
     * @param {Number[]} [cfg.positions] Flat array of uncompressed 3D vertex positions positions. Required for all primitive types. Overridden by ````positionsCompressed````.
     * @param {Number[]} [cfg.positionsCompressed] Flat array of quantized 3D vertex positions. Overrides ````positions````, and must be accompanied by ````positionsDecodeMatrix````.
     * @param {Number[]} [cfg.positionsDecodeMatrix] A 4x4 matrix for decompressing ````positionsCompressed````. Must be accompanied by ````positionsCompressed````.
     * @param {Number[]} [cfg.normals] Flat array of normal vectors. Only used with "triangles", "solid" and "surface" primitives. When no normals are given, the geometry will be flat shaded using auto-generated face-aligned normals.
     * @param {Number[]} [cfg.normalsCompressed] Flat array of oct-encoded normal vectors. Overrides ````normals````. Only used with "triangles", "solid" and "surface" primitives. When no normals are given, the geometry will be flat shaded using auto-generated face-aligned normals.
     * @param {Number[]} [cfg.colors] Flat array of uncompressed RGBA vertex colors, as float values in range ````[0..1]````. Ignored when ````geometryId```` is given. Overridden by ````color```` and ````colorsCompressed````.
     * @param {Number[]} [cfg.colorsCompressed] Flat array of compressed RGBA vertex colors, as unsigned short integers in range ````[0..255]````. Ignored when ````geometryId```` is given. Overrides ````colors```` and is overridden by ````color````.
     * @param {Number[]} [cfg.uv] Flat array of uncompressed vertex UV coordinates. Only used with "triangles", "solid" and "surface" primitives. Required for textured rendering.
     * @param {Number[]} [cfg.uvCompressed] Flat array of compressed vertex UV coordinates. Only used with "triangles", "solid" and "surface" primitives. Overrides ````uv````. Must be accompanied by ````uvDecodeMatrix````. Only used with "triangles", "solid" and "surface" primitives. Required for textured rendering.
     * @param {Number[]} [cfg.uvDecodeMatrix] A 3x3 matrix for decompressing ````uvCompressed````.
     * @param {Number[]} [cfg.indices] Array of primitive connectivity indices. Not required for `points` primitives.
     * @param {Number[]} [cfg.edgeIndices] Array of edge line indices. Used only with 'triangles', 'solid' and 'surface' primitives. Automatically generated internally if not supplied, using the optional ````edgeThreshold```` given to the ````SceneModel```` constructor.
     */
    createGeometry(cfg) {
        if (cfg.id === undefined || cfg.id === null) {
            this.error("[createGeometry] Config missing: id");
            return;
        }
        if (this._geometries[cfg.id]) {
            this.error("[createGeometry] Geometry already created: " + cfg.id);
            return;
        }
        if (cfg.primitive === undefined || cfg.primitive === null) {
            cfg.primitive = "triangles";
        }
        if (cfg.primitive !== "points" && cfg.primitive !== "lines" && cfg.primitive !== "triangles" && cfg.primitive !== "solid" && cfg.primitive !== "surface") {
            this.error(`[createGeometry] Unsupported value for 'primitive': '${cfg.primitive}' - supported values are 'points', 'lines', 'triangles', 'solid' and 'surface'. Defaulting to 'triangles'.`);
            return;
        }
        if (!cfg.positions && !cfg.positionsCompressed && !cfg.buckets) {
            this.error("[createGeometry] Param expected: `positions`,  `positionsCompressed' or 'buckets");
            return null;
        }
        if (cfg.positionsCompressed && !cfg.positionsDecodeMatrix && !cfg.positionsDecodeBoundary) {
            this.error("[createGeometry] Param expected: `positionsDecodeMatrix` or 'positionsDecodeBoundary' (required for `positionsCompressed')");
            return null;
        }
        if (cfg.positionsDecodeMatrix && cfg.positionsDecodeBoundary) {
            this.error("[createGeometry] Only one of these params expected: `positionsDecodeMatrix` or 'positionsDecodeBoundary' (required for `positionsCompressed')");
            return null;
        }
        if (cfg.uvCompressed && !cfg.uvDecodeMatrix) {
            this.error("[createGeometry] Param expected: `uvDecodeMatrix` (required for `uvCompressed')");
            return null;
        }
        if (!cfg.buckets && !cfg.indices && (cfg.primitive === "triangles" || cfg.primitive === "solid" || cfg.primitive === "surface")) {
            cfg.indices = this._createDefaultIndices((cfg.positions || cfg.positionsCompressed).length / 3);
        }
        if (!cfg.buckets && !cfg.indices && cfg.primitive !== "points") {
            this.error(`[createGeometry] Param expected: indices (required for '${cfg.primitive}' primitive type)`);
            return null;
        }
        if (cfg.positionsDecodeBoundary) {
            cfg.positionsDecodeMatrix = createPositionsDecodeMatrix(cfg.positionsDecodeBoundary, math.mat4());
        }
        if (cfg.positions) {
            const aabb = math.collapseAABB3();
            cfg.positionsDecodeMatrix = math.mat4();
            math.expandAABB3Points3(aabb, cfg.positions);
            cfg.positionsCompressed = quantizePositions(cfg.positions, aabb, cfg.positionsDecodeMatrix);
            cfg.aabb = aabb;
        } else if (cfg.positionsCompressed) {
            const aabb = math.collapseAABB3();
            cfg.positionsDecodeMatrix = new Float64Array(cfg.positionsDecodeMatrix);
            cfg.positionsCompressed = new Uint16Array(cfg.positionsCompressed);
            math.expandAABB3Points3(aabb, cfg.positionsCompressed);
            geometryCompressionUtils.decompressAABB(aabb, cfg.positionsDecodeMatrix);
            cfg.aabb = aabb;
        } else if (cfg.buckets) {
            const aabb = math.collapseAABB3();
            this._dtxBuckets[cfg.id] = cfg.buckets;
            for (let i = 0, len = cfg.buckets.length; i < len; i++) {
                const bucket = cfg.buckets[i];
                if (bucket.positions) {
                    math.expandAABB3Points3(aabb, bucket.positions);
                } else if (bucket.positionsCompressed) {
                    math.expandAABB3Points3(aabb, bucket.positionsCompressed);
                }
            }
            if (cfg.positionsDecodeMatrix) {
                geometryCompressionUtils.decompressAABB(aabb, cfg.positionsDecodeMatrix);
            }
            cfg.aabb = aabb;
        }
        if (cfg.colorsCompressed && cfg.colorsCompressed.length > 0) {
            cfg.colorsCompressed = new Uint8Array(cfg.colorsCompressed);
        } else if (cfg.colors && cfg.colors.length > 0) {
            const colors = cfg.colors;
            const colorsCompressed = new Uint8Array(colors.length);
            for (let i = 0, len = colors.length; i < len; i++) {
                colorsCompressed[i] = colors[i] * 255;
            }
            cfg.colorsCompressed = colorsCompressed;
        }
        if (!cfg.buckets && !cfg.edgeIndices && (cfg.primitive === "triangles" || cfg.primitive === "solid" || cfg.primitive === "surface")) {
            if (cfg.positions) {
                cfg.edgeIndices = buildEdgeIndices(cfg.positions, cfg.indices, null, 5.0);
            } else {
                cfg.edgeIndices = buildEdgeIndices(cfg.positionsCompressed, cfg.indices, cfg.positionsDecodeMatrix, 2.0);
            }
        }
        if (cfg.uv) {
            const bounds = geometryCompressionUtils.getUVBounds(cfg.uv);
            const result = geometryCompressionUtils.compressUVs(cfg.uv, bounds.min, bounds.max);
            cfg.uvCompressed = result.quantized;
            cfg.uvDecodeMatrix = result.decodeMatrix;
        } else if (cfg.uvCompressed) {
            cfg.uvCompressed = new Uint16Array(cfg.uvCompressed);
            cfg.uvDecodeMatrix = new Float64Array(cfg.uvDecodeMatrix);
        }
        if (cfg.normals) { // HACK
            cfg.normals = null;
        }
        this._geometries [cfg.id] = cfg;
        this._numTriangles += (cfg.indices ? Math.round(cfg.indices.length / 3) : 0);
        this.numGeometries++;
    }

    /**
     * Creates a texture within this SceneModel.
     *
     * We can then supply the texture ID to {@link SceneModel#createTextureSet} when we want to create texture sets that use the texture.
     *
     * @param {*} cfg Texture properties.
     * @param {String|Number} cfg.id Mandatory ID for the texture, to refer to with {@link SceneModel#createTextureSet}.
     * @param {String} [cfg.src] Image file for the texture. Assumed to be transcoded if not having a recognized image file
     * extension (jpg, jpeg, png etc.). If transcoded, then assumes ````SceneModel```` is configured with a {@link TextureTranscoder}.
     * @param {ArrayBuffer[]} [cfg.buffers] Transcoded texture data. Assumes ````SceneModel```` is
     * configured with a {@link TextureTranscoder}. This parameter is given as an array of buffers so we can potentially support multi-image textures, such as cube maps.
     * @param {HTMLImageElement} [cfg.image] HTML Image object to load into this texture. Overrides ````src```` and ````buffers````. Never transcoded.
     * @param {Number} [cfg.minFilter=LinearMipmapLinearFilter] How the texture is sampled when a texel covers less than one pixel.
     * Supported values are {@link LinearMipmapLinearFilter}, {@link LinearMipMapNearestFilter}, {@link NearestMipMapNearestFilter}, {@link NearestMipMapLinearFilter} and {@link LinearMipMapLinearFilter}.
     * @param {Number} [cfg.magFilter=LinearFilter] How the texture is sampled when a texel covers more than one pixel. Supported values are {@link LinearFilter} and {@link NearestFilter}.
     * @param {Number} [cfg.wrapS=RepeatWrapping] Wrap parameter for texture coordinate *S*. Supported values are {@link ClampToEdgeWrapping}, {@link MirroredRepeatWrapping} and {@link RepeatWrapping}.
     * @param {Number} [cfg.wrapT=RepeatWrapping] Wrap parameter for texture coordinate *T*. Supported values are {@link ClampToEdgeWrapping}, {@link MirroredRepeatWrapping} and {@link RepeatWrapping}..
     * @param {Number} [cfg.wrapR=RepeatWrapping] Wrap parameter for texture coordinate *R*. Supported values are {@link ClampToEdgeWrapping}, {@link MirroredRepeatWrapping} and {@link RepeatWrapping}.
     * @param {Boolean} [cfg.flipY=false] Flips this Texture's source data along its vertical axis when ````true````.
     * @param  {Number} [cfg.encoding=LinearEncoding] Encoding format. Supported values are {@link LinearEncoding} and {@link sRGBEncoding}.
     */
    createTexture(cfg) {
        const textureId = cfg.id;
        if (textureId === undefined || textureId === null) {
            this.error("[createTexture] Config missing: id");
            return;
        }
        if (this._textures[textureId]) {
            this.error("[createTexture] Texture already created: " + textureId);
            return;
        }
        if (!cfg.src && !cfg.image && !cfg.buffers) {
            this.error("[createTexture] Param expected: `src`, `image' or 'buffers'");
            return null;
        }
        let minFilter = cfg.minFilter || LinearMipmapLinearFilter;
        if (minFilter !== LinearFilter &&
            minFilter !== LinearMipMapNearestFilter &&
            minFilter !== LinearMipmapLinearFilter &&
            minFilter !== NearestMipMapLinearFilter &&
            minFilter !== NearestMipMapNearestFilter) {
            this.error(`[createTexture] Unsupported value for 'minFilter' - 
            supported values are LinearFilter, LinearMipMapNearestFilter, NearestMipMapNearestFilter, 
            NearestMipMapLinearFilter and LinearMipmapLinearFilter. Defaulting to LinearMipmapLinearFilter.`);
            minFilter = LinearMipmapLinearFilter;
        }
        let magFilter = cfg.magFilter || LinearFilter;
        if (magFilter !== LinearFilter && magFilter !== NearestFilter) {
            this.error(`[createTexture] Unsupported value for 'magFilter' - supported values are LinearFilter and NearestFilter. Defaulting to LinearFilter.`);
            magFilter = LinearFilter;
        }
        let wrapS = cfg.wrapS || RepeatWrapping;
        if (wrapS !== ClampToEdgeWrapping && wrapS !== MirroredRepeatWrapping && wrapS !== RepeatWrapping) {
            this.error(`[createTexture] Unsupported value for 'wrapS' - supported values are ClampToEdgeWrapping, MirroredRepeatWrapping and RepeatWrapping. Defaulting to RepeatWrapping.`);
            wrapS = RepeatWrapping;
        }
        let wrapT = cfg.wrapT || RepeatWrapping;
        if (wrapT !== ClampToEdgeWrapping && wrapT !== MirroredRepeatWrapping && wrapT !== RepeatWrapping) {
            this.error(`[createTexture] Unsupported value for 'wrapT' - supported values are ClampToEdgeWrapping, MirroredRepeatWrapping and RepeatWrapping. Defaulting to RepeatWrapping.`);
            wrapT = RepeatWrapping;
        }
        let wrapR = cfg.wrapR || RepeatWrapping;
        if (wrapR !== ClampToEdgeWrapping && wrapR !== MirroredRepeatWrapping && wrapR !== RepeatWrapping) {
            this.error(`[createTexture] Unsupported value for 'wrapR' - supported values are ClampToEdgeWrapping, MirroredRepeatWrapping and RepeatWrapping. Defaulting to RepeatWrapping.`);
            wrapR = RepeatWrapping;
        }
        let encoding = cfg.encoding || LinearEncoding;
        if (encoding !== LinearEncoding && encoding !== sRGBEncoding) {
            this.error("[createTexture] Unsupported value for 'encoding' - supported values are LinearEncoding and sRGBEncoding. Defaulting to LinearEncoding.");
            encoding = LinearEncoding;
        }
        const texture = new Texture2D({
            gl: this.scene.canvas.gl,
            minFilter,
            magFilter,
            wrapS,
            wrapT,
            wrapR,
            // flipY: cfg.flipY,
            encoding
        });
        if (cfg.preloadColor) {
            texture.setPreloadColor(cfg.preloadColor);
        }
        if (cfg.image) { // Ignore transcoder for Images
            const image = cfg.image;
            image.crossOrigin = "Anonymous";
            if (image.compressed) {
                // see `parsedImage` in @loaders.gl/gltf/src/lib/parsers/parse-gltf.ts
                // NOTE: @loaders.gl in its current version discards potential mipmaps, leaving only a single one
                const data = image.data;
                texture.setCompressedData({
                    mipmaps: data,
                    props: {
                        format: data[0].format,
                        minFilter: minFilter,
                        magFilter: magFilter
                    }
                });
            } else {
                texture.setImage(image, {minFilter, magFilter, wrapS, wrapT, wrapR, flipY: cfg.flipY, encoding});
            }
        } else if (cfg.src) {
            const ext = cfg.src.split('.').pop();
            switch (ext) { // Don't transcode recognized image file types
                case "jpeg":
                case "jpg":
                case "png":
                case "gif":
                    const image = new Image();
                    image.onload = () => {
                        texture.setImage(image, {
                            minFilter,
                            magFilter,
                            wrapS,
                            wrapT,
                            wrapR,
                            flipY: cfg.flipY,
                            encoding
                        });
                        this.glRedraw();
                    };
                    image.src = cfg.src; // URL or Base64 string
                    break;
                default: // Assume other file types need transcoding
                    if (!this._textureTranscoder) {
                        this.error(`[createTexture] Can't create texture from 'src' - SceneModel needs to be configured with a TextureTranscoder for this file type ('${ext}')`);
                    } else {
                        utils.loadArraybuffer(cfg.src, (arrayBuffer) => {
                                if (!arrayBuffer.byteLength) {
                                    this.error(`[createTexture] Can't create texture from 'src': file data is zero length`);
                                    return;
                                }
                                this._textureTranscoder.transcode([arrayBuffer], texture).then(() => {
                                    this.glRedraw();
                                });
                            },
                            function (errMsg) {
                                this.error(`[createTexture] Can't create texture from 'src': ${errMsg}`);
                            });
                    }
                    break;
            }
        } else if (cfg.buffers) { // Buffers implicitly require transcoding
            if (!this._textureTranscoder) {
                this.error(`[createTexture] Can't create texture from 'buffers' - SceneModel needs to be configured with a TextureTranscoder for this option`);
            } else {
                this._textureTranscoder.transcode(cfg.buffers, texture).then(() => {
                    this.glRedraw();
                });
            }
        }
        this._textures[textureId] = new SceneModelTexture({id: textureId, texture});
    }

    /**
     * Creates a texture set within this SceneModel.
     *
     * * Stores the new {@link SceneModelTextureSet} in {@link SceneModel#textureSets}.
     *
     * A texture set is a collection of textures that can be shared among meshes. We can then supply the texture set
     * ID to {@link SceneModel#createMesh} when we want to create meshes that use the texture set.
     *
     * The textures can work as a texture atlas, where each mesh can have geometry UVs that index
     * a different part of the textures. This allows us to minimize the number of textures in our models, which
     * means faster rendering.
     *
     * @param {*} cfg Texture set properties.
     * @param {String|Number} cfg.id Mandatory ID for the texture set, to refer to with {@link SceneModel#createMesh}.
     * @param {*} [cfg.colorTextureId] ID of *RGBA* base color texture, with color in *RGB* and alpha in *A*.
     * @param {*} [cfg.metallicRoughnessTextureId] ID of *RGBA* metal-roughness texture, with the metallic factor in *R*, and roughness factor in *G*.
     * @param {*} [cfg.normalsTextureId] ID of *RGBA* normal map texture, with normal map vectors in *RGB*.
     * @param {*} [cfg.emissiveTextureId] ID of *RGBA* emissive map texture, with emissive color in *RGB*.
     * @param {*} [cfg.occlusionTextureId] ID of *RGBA* occlusion map texture, with occlusion factor in *R*.
     * @returns {SceneModelTransform} The new texture set.
     */
    createTextureSet(cfg) {
        const textureSetId = cfg.id;
        if (textureSetId === undefined || textureSetId === null) {
            this.error("[createTextureSet] Config missing: id");
            return false;
        }
        if (this._textureSets[textureSetId]) {
            this.error(`[createTextureSet] Texture set already created: ${textureSetId}`);
            return false;
        }

        const getTexture = (cfgId, defaultKey) => {
            const id = cfgId ?? defaultKey;
            if (id in this._textures) {
                return this._textures[id];
            } else {
                throw cfgId;
            }
        };

        try {
            const textureSet = new SceneModelTextureSet({
                id: textureSetId,
                model: this,
                alphaCutoff: cfg.alphaCutoff,
                colorTexture:             getTexture(cfg.colorTextureId,             DEFAULT_COLOR_TEXTURE_ID),
                metallicRoughnessTexture: getTexture(cfg.metallicRoughnessTextureId, DEFAULT_METAL_ROUGH_TEXTURE_ID),
                normalsTexture:           getTexture(cfg.normalsTextureId,           DEFAULT_NORMALS_TEXTURE_ID),
                emissiveTexture:          getTexture(cfg.emissiveTextureId,          DEFAULT_EMISSIVE_TEXTURE_ID),
                occlusionTexture:         getTexture(cfg.occlusionTextureId,         DEFAULT_OCCLUSION_TEXTURE_ID)
            });
            this._textureSets[textureSetId] = textureSet;
            return textureSet;
        } catch (id) {
            this.error(`[createTextureSet] Texture not found: ${id} - ensure that you create it first with createTexture()`);
            return false;
        }
    }

    /**
     * Creates a new {@link SceneModelTransform} within this SceneModel.
     *
     * * Stores the new {@link SceneModelTransform} in {@link SceneModel#transforms}.
     * * Can be connected into hierarchies
     * * Each {@link SceneModelTransform} can be used by unlimited {@link SceneModelMesh}es
     *
     * @param {*} cfg Transform creation parameters.
     * @param {String} cfg.id Mandatory ID for the new transform. Must not clash with any existing components within the {@link Scene}.
     * @param {String} [cfg.parentTransformId] ID of a parent transform, previously created with {@link SceneModel#createTextureSet}.
     * @param {Number[]} [cfg.position=[0,0,0]] Local 3D position of the mesh. Overridden by ````transformId````.
     * @param {Number[]} [cfg.scale=[1,1,1]] Scale of the transform.
     * @param {Number[]} [cfg.rotation=[0,0,0]] Rotation of the transform as Euler angles given in degrees, for each of the X, Y and Z axis.
     * @param {Number[]} [cfg.matrix=[1,0,0,0,0,1,0,0,0,0,1,0,0,0,0,1]] Modelling transform matrix. Overrides the ````position````, ````scale```` and ````rotation```` parameters.
     * @returns {SceneModelTransform} The new transform.
     */
    createTransform(cfg) {
        if (cfg.id === undefined || cfg.id === null) {
            this.error("[createTransform] SceneModel.createTransform() config missing: id");
            return;
        }
        if (this._transforms[cfg.id]) {
            this.error(`[createTransform] SceneModel already has a transform with this ID: ${cfg.id}`);
            return;
        }
        let parentTransform;
        if (cfg.parentTransformId) {
            parentTransform = this._transforms[cfg.parentTransformId];
            if (!parentTransform) {
                this.error("[createTransform] SceneModel.createTransform() config missing: id");
                return;
            }
        }
        const transform = new SceneModelTransform({
            id: cfg.id,
            model: this,
            parent: parentTransform,
            matrix: cfg.matrix,
            position: cfg.position,
            scale: cfg.scale,
            rotation: cfg.rotation,
            quaternion: cfg.quaternion
        });
        this._transforms[transform.id] = transform;
        return transform;
    }

    /**
     * Creates a new {@link SceneModelMesh} within this SceneModel.
     *
     * * It prepares and saves data for a SceneModelMesh {@link SceneModel#meshes} creation. SceneModelMesh will be created only once the SceneModelEntity (which references this particular SceneModelMesh) will be created.
     * * The SceneModelMesh can either define its own geometry or share it with other SceneModelMeshes. To define own geometry, provide the
     * various geometry arrays to this method. To share a geometry, provide the ID of a geometry created earlier
     * with {@link SceneModel#createGeometry}.
     * * If you accompany the arrays with an  ````origin````, then ````createMesh()```` will assume
     * that the geometry ````positions```` are in relative-to-center (RTC) coordinates, with ````origin```` being the
     * origin of their RTC coordinate system.
     *
     * @param {object} cfg Object properties.
     * @param {String} cfg.id Mandatory ID for the new mesh. Must not clash with any existing components within the {@link Scene}.
     * @param {String|Number} [cfg.textureSetId] ID of a {@link SceneModelTextureSet} previously created with {@link SceneModel#createTextureSet}.
     * @param {String|Number} [cfg.transformId] ID of a {@link SceneModelTransform} to instance, previously created with {@link SceneModel#createTransform}. Overrides all other transform parameters given to this method.
     * @param {String|Number} [cfg.geometryId] ID of a geometry to instance, previously created with {@link SceneModel#createGeometry}. Overrides all other geometry parameters given to this method.
     * @param {String} cfg.primitive The primitive type. Accepted values are 'points', 'lines', 'triangles', 'solid' and 'surface'.
     * @param {Number[]} [cfg.positions] Flat array of uncompressed 3D vertex positions positions. Required for all primitive types. Overridden by ````positionsCompressed````.
     * @param {Number[]} [cfg.positionsCompressed] Flat array of quantized 3D vertex positions. Overrides ````positions````, and must be accompanied by ````positionsDecodeMatrix````.
     * @param {Number[]} [cfg.positionsDecodeMatrix] A 4x4 matrix for decompressing ````positionsCompressed````. Must be accompanied by ````positionsCompressed````.
     * @param {Number[]} [cfg.normals] Flat array of normal vectors. Only used with "triangles", "solid" and "surface" primitives. When no normals are given, the geometry will be flat shaded using auto-generated face-aligned normals.
     * @param {Number[]} [cfg.normalsCompressed] Flat array of oct-encoded normal vectors. Overrides ````normals````. Only used with "triangles", "solid" and "surface" primitives. When no normals are given, the geometry will be flat shaded using auto-generated face-aligned normals.
     * @param {Number[]} [cfg.colors] Flat array of uncompressed RGBA vertex colors, as float values in range ````[0..1]````. Ignored when ````geometryId```` is given. Overridden by ````color```` and ````colorsCompressed````.
     * @param {Number[]} [cfg.colorsCompressed] Flat array of compressed RGBA vertex colors, as unsigned short integers in range ````[0..255]````. Ignored when ````geometryId```` is given. Overrides ````colors```` and is overridden by ````color````.
     * @param {Number[]} [cfg.uv] Flat array of uncompressed vertex UV coordinates. Only used with "triangles", "solid" and "surface" primitives. Required for textured rendering.
     * @param {Number[]} [cfg.uvCompressed] Flat array of compressed vertex UV coordinates. Only used with "triangles", "solid" and "surface" primitives. Overrides ````uv````. Must be accompanied by ````uvDecodeMatrix````. Only used with "triangles", "solid" and "surface" primitives. Required for textured rendering.
     * @param {Number[]} [cfg.uvDecodeMatrix] A 3x3 matrix for decompressing ````uvCompressed````.
     * @param {Number[]} [cfg.indices] Array of primitive connectivity indices. Not required for `points` primitives.
     * @param {Number[]} [cfg.edgeIndices] Array of edge line indices. Used only with 'triangles', 'solid' and 'surface' primitives. Automatically generated internally if not supplied, using the optional ````edgeThreshold```` given to the ````SceneModel```` constructor.
     * @param {Number[]} [cfg.origin] Optional geometry origin, relative to {@link SceneModel#origin}. When this is given, then ````positions```` are assumed to be relative to this.
     * @param {Number[]} [cfg.position=[0,0,0]] Local 3D position of the mesh. Overridden by ````transformId````.
     * @param {Number[]} [cfg.scale=[1,1,1]] Scale of the mesh.  Overridden by ````transformId````.
     * @param {Number[]} [cfg.rotation=[0,0,0]] Rotation of the mesh as Euler angles given in degrees, for each of the X, Y and Z axis.  Overridden by ````transformId````.
     * @param {Number[]} [cfg.quaternion] Rotation of the mesh as a quaternion.  Overridden by ````rotation````.
     * @param {Number[]} [cfg.matrix=[1,0,0,0,0,1,0,0,0,0,1,0,0,0,0,1]] Mesh modelling transform matrix. Overrides the ````position````, ````scale```` and ````rotation```` parameters. Also  overridden by ````transformId````.
     * @param {Number[]} [cfg.color=[1,1,1]] RGB color in range ````[0..1, 0..1, 0..1]````. Overridden by texture set ````colorTexture````. Overrides ````colors```` and ````colorsCompressed````.
     * @param {Number} [cfg.opacity=1] Opacity in range ````[0..1]````. Overridden by texture set ````colorTexture````.
     * @param {Number} [cfg.metallic=0] Metallic factor in range ````[0..1]````. Overridden by texture set ````metallicRoughnessTexture````.
     * @param {Number} [cfg.roughness=1] Roughness factor in range ````[0..1]````. Overridden by texture set ````metallicRoughnessTexture````.
     * @returns {SceneModelMesh} The new mesh.
     */
    createMesh(cfg) {

        if (cfg.id === undefined || cfg.id === null) {
            this.error("[createMesh] SceneModel.createMesh() config missing: id");
            return false;
        }

        if (this._meshes[cfg.id]) {
            this.error(`[createMesh] SceneModel already has a mesh with this ID: ${cfg.id}`);
            return false;
        }

        const geometryId = cfg.geometryId;
        const instancing = geometryId !== undefined;

        if (instancing) {
            if (cfg.positions || cfg.positionsCompressed || cfg.indices || cfg.edgeIndices || cfg.normals || cfg.normalsCompressed || cfg.uv || cfg.uvCompressed || cfg.positionsDecodeMatrix) {
                this.error(`Mesh geometry parameters not expected when instancing a geometry (not expected: positions, positionsCompressed, indices, edgeIndices, normals, normalsCompressed, uv, uvCompressed, positionsDecodeMatrix)`);
                return false;
            }

            cfg.geometry = this._geometries[geometryId];
            if (!cfg.geometry) {
                this.error(`[createMesh] Geometry not found: ${geometryId} - ensure that you create it first with createGeometry()`);
                return false;
            }
        } else {
            cfg.primitive ??= "triangles";
        }

        const primitive = instancing ? cfg.geometry.primitive : cfg.primitive;
        const isTriangular = (primitive === "triangles") || (primitive === "solid") || (primitive === "surface");
        const textureSetId = cfg.textureSetId;
        const useDTX = this._dtxEnabled && isTriangular && (! textureSetId);

        cfg.origin = cfg.origin ? math.addVec3(this._origin, cfg.origin, math.vec3()) : this._origin;

        if (! instancing) {

            // Batched geometry

            if (primitive !== "points" && primitive !== "lines" && primitive !== "triangles" && primitive !== "solid" && primitive !== "surface") {
                this.error(`Unsupported value for 'primitive': '${primitive}'  ('geometryId' is absent) - supported values are 'points', 'lines', 'triangles', 'solid' and 'surface'.`);
                return false;
            }
            if (!cfg.positions && !cfg.positionsCompressed && !cfg.buckets) {
                this.error("Param expected: 'positions',  'positionsCompressed' or `buckets`  ('geometryId' is absent)");
                return false;
            }
            if (cfg.positions && (cfg.positionsDecodeMatrix || cfg.positionsDecodeBoundary)) {
                this.error("Illegal params: 'positions' not expected with 'positionsDecodeMatrix'/'positionsDecodeBoundary' ('geometryId' is absent)");
                return false;
            }
            if (cfg.positionsCompressed && !cfg.positionsDecodeMatrix && !cfg.positionsDecodeBoundary) {
                this.error("Param expected: 'positionsCompressed' should be accompanied by 'positionsDecodeMatrix'/'positionsDecodeBoundary' ('geometryId' is absent)");
                return false;
            }
            if (cfg.uvCompressed && !cfg.uvDecodeMatrix) {
                this.error("Param expected: 'uvCompressed' should be accompanied by `uvDecodeMatrix` ('geometryId' is absent)");
                return false;
            }
            if (!cfg.buckets && !cfg.indices) {
                if (isTriangular) {
                    cfg.indices = this._createDefaultIndices((cfg.positions || cfg.positionsCompressed).length / 3);
                } else if (primitive === "lines") {
                    this.error(`Param expected: indices (required for '${primitive}' primitive type)`);
                    return false;
                }
            }
            if ((cfg.matrix || cfg.position || cfg.rotation || cfg.scale) && (cfg.positionsCompressed || cfg.positionsDecodeBoundary)) {
                this.error("Unexpected params: 'matrix', 'rotation', 'scale', 'position' not allowed with 'positionsCompressed'");
                return false;
            }

            // MATRIX - optional for batching

            if (cfg.matrix) {
                cfg.meshMatrix = cfg.matrix;
            } else if (cfg.scale || cfg.rotation || cfg.position || cfg.quaternion) {
                const scale = cfg.scale || DEFAULT_SCALE;
                const position = cfg.position || DEFAULT_POSITION;
                const quaternion = (cfg.rotation
                                    ? math.eulerToQuaternion(cfg.rotation, "XYZ", tempQuaternion)
                                    : cfg.quaternion || DEFAULT_QUATERNION);
                cfg.meshMatrix = math.composeMat4(position, quaternion, scale, math.mat4());
            }

            if (cfg.positionsDecodeBoundary) {
                cfg.positionsDecodeMatrix = createPositionsDecodeMatrix(cfg.positionsDecodeBoundary, math.mat4());
            }

            // RTC && COMPRESSION

            if (cfg.positions) {
                const rtcPositions = [];
                const rtcNeeded = worldToRTCPositions(cfg.positions, rtcPositions, tempVec3a);
                if (rtcNeeded) {
                    cfg.positions = rtcPositions;
                    cfg.origin = math.addVec3(cfg.origin, tempVec3a, math.vec3());
                }

                const aabb = math.collapseAABB3();
                if (useDTX) {
                    cfg.positionsDecodeMatrix = math.mat4();
                    math.expandAABB3Points3(aabb, cfg.positions);
                    cfg.positionsCompressed = quantizePositions(cfg.positions, aabb, cfg.positionsDecodeMatrix);
                } else {
                    if (cfg.meshMatrix) {
                        math.transformPositions3(cfg.meshMatrix, cfg.positions, cfg.positions);
                        cfg.meshMatrix = null; // Positions now baked, don't need any more
                    }
                    math.expandAABB3Points3(aabb, cfg.positions);
                }
                cfg.aabb = aabb;
            } else if (cfg.positionsCompressed) {
                const aabb = math.collapseAABB3();
                math.expandAABB3Points3(aabb, cfg.positionsCompressed);
                geometryCompressionUtils.decompressAABB(aabb, cfg.positionsDecodeMatrix);
                cfg.aabb = aabb;
            }

            if (useDTX && cfg.buckets) {
                const aabb = math.collapseAABB3();
                cfg.buckets.forEach(bucket => {
                    const positions = bucket.positions || bucket.positionsCompressed;
                    if (positions) {
                        math.expandAABB3Points3(aabb, positions);
                    }
                });
                if (cfg.positionsDecodeMatrix) {
                    geometryCompressionUtils.decompressAABB(aabb, cfg.positionsDecodeMatrix);
                }
                cfg.aabb = aabb;
            }

            // EDGES

            if (isTriangular && (! cfg.buckets)) {
                cfg.edgeIndices ||= buildEdgeIndices(cfg.positions || cfg.positionsCompressed, cfg.indices, cfg.positions ? null : cfg.positionsDecodeMatrix, 2.0);
            }

        } else {

            // INSTANCING

            cfg.positionsDecodeMatrix = cfg.geometry.positionsDecodeMatrix;

            cfg.aabb = math.AABB3(cfg.geometry.aabb);

            const transformId = cfg.transformId;
            if (transformId) {

                // TRANSFORM

                cfg.transform = this._transforms[transformId];

                if (!cfg.transform) {
                    this.error(`[createMesh] Transform not found: ${transformId} - ensure that you create it first with createTransform()`);
                    return false;
                }

            } else {

                // MATRIX

                if (cfg.matrix) {
                    cfg.meshMatrix = cfg.matrix;
                } else if (cfg.scale || cfg.rotation || cfg.position || cfg.quaternion) {
                    const scale = cfg.scale || DEFAULT_SCALE;
                    const position = cfg.position || DEFAULT_POSITION;
                    const quaternion = (cfg.rotation
                                        ? math.eulerToQuaternion(cfg.rotation, "XYZ", tempQuaternion)
                                        : cfg.quaternion || DEFAULT_QUATERNION);
                    cfg.meshMatrix = math.composeMat4(position, quaternion, scale, math.mat4());
                }
            }
        }

        if (cfg.meshMatrix) {
            math.AABB3ToOBB3(cfg.aabb, tempOBB3);
            math.transformOBB3(cfg.meshMatrix, tempOBB3, tempOBB3);
            math.OBB3ToAABB3(tempOBB3, cfg.aabb);
        }

        cfg.color = cfg.color ? new Uint8Array(cfg.color.slice(0, 3).map(v => Math.floor(v * 255))) : defaultCompressedColor;
        cfg.opacity = Math.floor((cfg.opacity ?? 1) * 255);

        if (useDTX) {
            cfg.type = DTX;

            // BUCKETING
            if (instancing) {
                cfg.buckets = this._dtxBuckets[geometryId]; // lazy generated, reused
            }
            if (!cfg.buckets) {
                cfg.buckets = createDTXBuckets(instancing ? cfg.geometry : cfg, this._enableVertexWelding, this._enableIndexBucketing);
                if (instancing) {
                    this._dtxBuckets[geometryId] = cfg.buckets;
                }
            }

        } else {
            cfg.type = instancing ? VBO_INSTANCED : VBO_BATCHED;

            // PBR
            cfg.metallic  = Math.floor((cfg.metallic  ?? 0) * 255);
            cfg.roughness = Math.floor((cfg.roughness ?? 1) * 255);

            // TEXTURE
            // cfg.textureSetId = cfg.textureSetId || DEFAULT_TEXTURE_SET_ID;
            if (textureSetId) {
                cfg.textureSet = this._textureSets[textureSetId];
                if ((! instancing) && (!cfg.textureSet)) {
                    this.error(`[createMesh] Texture set not found: ${textureSetId} - ensure that you create it first with createTextureSet()`);
                    return false;
                }
            }
        }

        cfg.numPrimitives = this._getNumPrimitives(cfg);

        const mesh = new SceneModelMesh(this, cfg.id, cfg.color, cfg.opacity, cfg.transform, cfg.textureSet);
        const pickId = this.scene._renderer.getPickID(mesh);
        mesh.pickId = pickId;
        mesh.origin = math.vec3(cfg.origin);
        mesh.layer = (cfg.type === DTX) ? this._getDTXLayer(cfg) : this._getVBOLayer(cfg.type === VBO_INSTANCED, cfg);
        mesh.aabb = cfg.aabb;
        cfg.pickColor = new Uint8Array([pickId & 0xFF, pickId >> 8 & 0xFF, pickId >> 16 & 0xFF, pickId >> 24 & 0xFF]); // Quantized pick color
        cfg.solid = (cfg.primitive === "solid");
        cfg.meshMatrix = cfg.transform ? cfg.transform.worldMatrix : cfg.meshMatrix;
        mesh.portionId = mesh.layer.createPortion(mesh, cfg);
        mesh.numPrimitives = cfg.numPrimitives;
        this._meshes[cfg.id] = mesh;
        this._unusedMeshes[cfg.id] = mesh;
        this._meshList.push(mesh);
        return mesh;
    }

    _getNumPrimitives(cfg) {
        let countIndices = 0;
        const primitive = cfg.geometry ? cfg.geometry.primitive : cfg.primitive;
        switch (primitive) {
            case "triangles":
            case "solid":
            case "surface":
                switch (cfg.type) {
                    case DTX:
                        for (let i = 0, len = cfg.buckets.length; i < len; i++) {
                            countIndices += cfg.buckets[i].indices.length;
                        }
                        break;
                    case VBO_BATCHED:
                        countIndices += cfg.indices.length;
                        break;
                    case VBO_INSTANCED:
                        countIndices += cfg.geometry.indices.length;
                        break;
                }
                return Math.round(countIndices / 3);
            case "points":
                switch (cfg.type) {
                    case DTX:
                        for (let i = 0, len = cfg.buckets.length; i < len; i++) {
                            countIndices += cfg.buckets[i].positionsCompressed.length;
                        }
                        break;
                    case VBO_BATCHED:
                        countIndices += cfg.positions ? cfg.positions.length : cfg.positionsCompressed.length;
                        break;
                    case VBO_INSTANCED:
                        const geometry = cfg.geometry;
                        countIndices += geometry.positions ? geometry.positions.length : geometry.positionsCompressed.length;
                        break;
                }
                return Math.round(countIndices);
            case "lines":
            case "line-strip":
                switch (cfg.type) {
                    case DTX:
                        for (let i = 0, len = cfg.buckets.length; i < len; i++) {
                            countIndices += cfg.buckets[i].indices.length;
                        }
                        break;
                    case VBO_BATCHED:
                        countIndices += cfg.indices.length;
                        break;
                    case VBO_INSTANCED:
                        countIndices += cfg.geometry.indices.length;
                        break;
                }
                return Math.round(countIndices / 2);
        }
        return 0;
    }

    _getDTXLayer(cfg) {
        const origin = cfg.origin;
        const primitive = cfg.geometry ? cfg.geometry.primitive : cfg.primitive;
        const layerId = `.${primitive}.${Math.round(origin[0])}.${Math.round(origin[1])}.${Math.round(origin[2])}`;
        let dtxLayer = this._dtxLayers[layerId];
        if (dtxLayer) {
            if (!dtxLayer.canCreatePortion(cfg)) {
                //  dtxLayer.finalize();
                delete this._dtxLayers[layerId];
                dtxLayer = null;
            } else {
                return dtxLayer;
            }
        }
        switch (primitive) {
            case "triangles":
            case "solid":
            case "surface":
                dtxLayer = new DTXLayer(this, primitive, origin);
                break;
            default:
                return;
        }
        this._dtxLayers[layerId] = dtxLayer;
        this.layerList.push(dtxLayer);
        this._layersToFinalize.push(dtxLayer);
        return dtxLayer;
    }

    _getVBOLayer(instancing, cfg) {
        const geometry = instancing && cfg.geometry;
        const primitive = instancing ? geometry.primitive : cfg.primitive;
        const origin = cfg.origin;
        const posDecode = (! instancing) && (cfg.positionsDecodeMatrix || cfg.positionsDecodeBoundary);
        const positionsDecodeHash = posDecode ? this._createHashStringFromMatrix(posDecode) : "-";
        const textureSetId = cfg.textureSetId || "-";
        const geometryId = instancing ? cfg.geometryId : "-";
        const layerId = (instancing ? "instancing" : "batching") + `.${Math.round(origin[0])}.${Math.round(origin[1])}.${Math.round(origin[2])}.${primitive}.${positionsDecodeHash}.${textureSetId}.${geometryId}.${((cfg.normalsCompressed || cfg.normals || [ ]).length > 0) ? "n" : "-"}`;

        if ((! instancing) && (layerId in this._vboLayers)) {
            const layer = this._vboLayers[layerId];
            const lenPositions = cfg.positionsCompressed ? cfg.positionsCompressed.length : cfg.positions.length;
            if (! layer.canCreatePortion(lenPositions, (primitive === "points") ? 0 : cfg.indices.length)) {
                layer.finalize();
                delete this._vboLayers[layerId];
            }
        }

        if (! (layerId in this._vboLayers)) {
            const layer = new VBOLayer(this, primitive, origin, {
                textureSet: cfg.textureSet,
                ...(instancing ? {
                    geometry: geometry,
                } : {
                    maxGeometryBatchSize: this._maxGeometryBatchSize,
                    positionsDecodeMatrix: cfg.positionsDecodeMatrix,  // Can be undefined
                    uvDecodeMatrix: cfg.uvDecodeMatrix, // Can be undefined
                })
            });
            this.layerList.push(layer);
            this._layersToFinalize.push(layer);
            this._vboLayers[layerId] = layer;
        }
        return this._vboLayers[layerId];
    }

    _createHashStringFromMatrix(matrix) {
        const matrixString = matrix.join(";");
        let hash = 0;
        for (let i = 0; i < matrixString.length; i++) {
            const char = matrixString.charCodeAt(i);
            hash = (hash << 5) - hash + char;
            hash |= 0; // Convert to 32-bit integer
        }
        const hashString = (hash >>> 0).toString(16);
        return hashString;
    }

    /**
     * Creates a {@link SceneModelEntity} within this SceneModel.
     *
     * * Gives the SceneModelEntity one or more {@link SceneModelMesh}es previously created with
     * {@link SceneModel#createMesh}. A SceneModelMesh can only belong to one SceneModelEntity, so you'll get an
     * error if you try to reuse a mesh among multiple SceneModelEntitys.
     * * The SceneModelEntity can have a {@link SceneModelTextureSet}, previously created with
     * {@link SceneModel#createTextureSet}. A SceneModelTextureSet can belong to multiple SceneModelEntitys.
     * * The SceneModelEntity can have a geometry, previously created with
     * {@link SceneModel#createTextureSet}. A geometry is a "virtual component" and can belong to multiple SceneModelEntitys.
     *
     * @param {Object} cfg SceneModelEntity configuration.
     * @param {String} cfg.id Optional ID for the new SceneModelEntity. Must not clash with any existing components within the {@link Scene}.
     * @param {String[]} cfg.meshIds IDs of one or more meshes created previously with {@link SceneModel@createMesh}.
     * @param {Boolean} [cfg.isObject] Set ````true```` if the {@link SceneModelEntity} represents an object, in which case it will be registered by {@link SceneModelEntity#id} in {@link Scene#objects} and can also have a corresponding {@link MetaObject} with matching {@link MetaObject#id}, registered by that ID in {@link MetaScene#metaObjects}.
     * @param {Boolean} [cfg.visible=true] Indicates if the SceneModelEntity is initially visible.
     * @param {Boolean} [cfg.culled=false] Indicates if the SceneModelEntity is initially culled from view.
     * @param {Boolean} [cfg.pickable=true] Indicates if the SceneModelEntity is initially pickable.
     * @param {Boolean} [cfg.clippable=true] Indicates if the SceneModelEntity is initially clippable.
     * @param {Boolean} [cfg.collidable=true] Indicates if the SceneModelEntity is initially included in boundary calculations.
     * @param {Boolean} [cfg.castsShadow=true] Indicates if the SceneModelEntity initially casts shadows.
     * @param {Boolean} [cfg.receivesShadow=true]  Indicates if the SceneModelEntity initially receives shadows.
     * @param {Boolean} [cfg.xrayed=false] Indicates if the SceneModelEntity is initially xrayed. XRayed appearance is configured by {@link SceneModel#xrayMaterial}.
     * @param {Boolean} [cfg.highlighted=false] Indicates if the SceneModelEntity is initially highlighted. Highlighted appearance is configured by {@link SceneModel#highlightMaterial}.
     * @param {Boolean} [cfg.selected=false] Indicates if the SceneModelEntity is initially selected. Selected appearance is configured by {@link SceneModel#selectedMaterial}.
     * @param {Boolean} [cfg.edges=false] Indicates if the SceneModelEntity's edges are initially emphasized. Edges appearance is configured by {@link SceneModel#edgeMaterial}.
     * @returns {SceneModelEntity} The new SceneModelEntity.
     */
    createEntity(cfg) {
        if (cfg.id === undefined) {
            cfg.id = math.createUUID();
        } else if (this.scene.components[cfg.id]) {
            this.error(`Scene already has a Component with this ID: ${cfg.id} - will assign random ID`);
            cfg.id = math.createUUID();
        }
        if (cfg.meshIds === undefined) {
            this.error("Config missing: meshIds");
            return null;
        }

        const notFalse = v => v !== false;
        let flags = 0;
        flags |= (this._visible     && notFalse(cfg.visible)     && ENTITY_FLAGS.VISIBLE);
        flags |= (this._pickable    && notFalse(cfg.pickable)    && ENTITY_FLAGS.PICKABLE);
        flags |= (this._culled      && notFalse(cfg.culled)      && ENTITY_FLAGS.CULLED);
        flags |= (this._clippable   && notFalse(cfg.clippable)   && ENTITY_FLAGS.CLIPPABLE);
        flags |= (this._collidable  && notFalse(cfg.collidable)  && ENTITY_FLAGS.COLLIDABLE);
        flags |= (this._xrayed      && notFalse(cfg.xrayed)      && ENTITY_FLAGS.XRAYED);
        flags |= (this._highlighted && notFalse(cfg.highlighted) && ENTITY_FLAGS.HIGHLIGHTED);
        flags |= (this._selected    && notFalse(cfg.selected)    && ENTITY_FLAGS.SELECTED);
        flags |= (this._edges       && notFalse(cfg.edges)       && ENTITY_FLAGS.EDGES);
        cfg.flags = flags;

        let meshes = [];
        for (let i = 0, len = cfg.meshIds.length; i < len; i++) {
            const meshId = cfg.meshIds[i];
            let mesh = this._meshes[meshId]; // Trying to get already created mesh
            if (!mesh) { // Checks if there is already created mesh for this meshId
                this.error(`Mesh with this ID not found: "${meshId}" - ignoring this mesh`); // There is no such cfg
                continue;
            }
            if (mesh.parent) {
                this.error(`Mesh with ID "${meshId}" already belongs to object with ID "${mesh.parent.id}" - ignoring this mesh`);
                continue;
            }
            meshes.push(mesh);
            delete this._unusedMeshes[meshId];
        }
        const lodCullable = true;
        const entity = new SceneModelEntity(
            this,
            cfg.isObject,
            cfg.id,
            meshes,
            cfg.flags,
            lodCullable); // Internally sets SceneModelEntity#parent to this SceneModel
        this._entityList.push(entity);
        this._entities[cfg.id] = entity;
        this._entitiesToFinalize.push(entity);
        this.numEntities++;
        return entity;
    }

    /**
     * Pre-renders all meshes that have been added, even if the SceneModel has not bee finalized yet.
     * This is use for progressively showing the SceneModel while it is being loaded or constructed.
     * @returns {boolean}
     */
    preFinalize() {
        if (this.destroyed) {
            return false;
        }
        if (this._layersToFinalize.length === 0) {
            return false;
        }
        this._createDummyEntityForUnusedMeshes();
        for (let i = 0, len = this._layersToFinalize.length; i < len; i++) {
            const layer = this._layersToFinalize[i];
            layer.finalize();
        }
        this._vboLayers = {};
        this._dtxLayers = {};
        this._layersToFinalize = [];
        for (let i = 0, len = this._entitiesToFinalize.length; i < len; i++) {
            const entity = this._entitiesToFinalize[i];
            entity._finalize();
        }
        for (let i = 0, len = this._entitiesToFinalize.length; i < len; i++) {
            const entity = this._entitiesToFinalize[i];
            entity._finalize2();
        }
        this._entitiesToFinalize = [];
        this.scene._aabbDirty = true;
        this._viewMatrixDirty = true;
        this._matrixDirty = true;
        this._aabbDirty = true;
        this._setWorldMatrixDirty();
        this._sceneModelDirty();
        this.position = this._position;
        // Sort layers to reduce WebGL shader switching when rendering them
        this.layerList.sort((a, b) => {
            if (a.sortId < b.sortId) {
                return -1;
            }
            if (a.sortId > b.sortId) {
                return 1;
            }
            return 0;
        });
        for (let i = 0, len = this.layerList.length; i < len; i++) {
            const layer = this.layerList[i];
            layer.layerIndex = i;
        }
        this.glRedraw();
        this._layersFinalized = true;
    }

    /**
     * Finalizes this SceneModel.
     *
     * Once finalized, you can't add anything more to this SceneModel.
     */
    finalize() {
        if (this.destroyed) {
            return;
        }
        this.preFinalize();
        this._geometries = {};
        this._dtxBuckets = {};
        this._textures = {};
        this._textureSets = {};
    }

    /** @private */
    stateSortCompare(drawable1, drawable2) {
    }

    /** @private */
    rebuildRenderFlags() {
        this.renderFlags.reset();
        this._updateRenderFlagsVisibleLayers();
        if (this.renderFlags.numLayers > 0 && this.renderFlags.numVisibleLayers === 0) {
            this.renderFlags.culled = true;
            return;
        }
        this._updateRenderFlags();
    }

    /**
     * @private
     */
    _updateRenderFlagsVisibleLayers() {
        const renderFlags = this.renderFlags;
        renderFlags.numLayers = this.layerList.length;
        renderFlags.numVisibleLayers = 0;
        for (let layerIndex = 0, len = this.layerList.length; layerIndex < len; layerIndex++) {
            const layer = this.layerList[layerIndex];
            const layerVisible = this._getActiveSectionPlanesForLayer(layer);
            if (layerVisible) {
                renderFlags.visibleLayers[renderFlags.numVisibleLayers++] = layerIndex;
            }
        }
    }

    /** @private */
    _createDummyEntityForUnusedMeshes() {
        const unusedMeshIds = Object.keys(this._unusedMeshes);
        if (unusedMeshIds.length > 0) {
            const entityId = `${this.id}-${math.createUUID()}`;
            this.warn(`Creating dummy SceneModelEntity "${entityId}" for unused SceneMeshes: [${unusedMeshIds.join(",")}]`)
            this.createEntity({
                id: entityId,
                meshIds: unusedMeshIds,
                isObject: true
            });
        }
        this._unusedMeshes = {};
    }

    _getActiveSectionPlanesForLayer(layer) {
        const renderFlags = this.renderFlags;
        const sectionPlanes = this.scene._sectionPlanesState.sectionPlanes;
        const numSectionPlanes = sectionPlanes.length;
        const baseIndex = layer.layerIndex * numSectionPlanes;
        if (numSectionPlanes > 0) {
            for (let i = 0; i < numSectionPlanes; i++) {
                const sectionPlane = sectionPlanes[i];
                if (!sectionPlane.active) {
                    renderFlags.sectionPlanesActivePerLayer[baseIndex + i] = false;
                } else {
                    renderFlags.sectionPlanesActivePerLayer[baseIndex + i] = true;
                    renderFlags.sectioned = true;
                }
            }
        }
        return true;
    }

    _updateRenderFlags() {
        if (this.numVisibleLayerPortions === 0) {
            return;
        }
        if (this.numCulledLayerPortions === this.numPortions) {
            return;
        }
        const renderFlags = this.renderFlags;
        renderFlags.colorOpaque = (this.numTransparentLayerPortions < this.numPortions);
        if (this.numTransparentLayerPortions > 0) {
            renderFlags.colorTransparent = true;
        }
        if (this.numXRayedLayerPortions > 0) {
            const xrayMaterial = this.scene.xrayMaterial._state;
            if (xrayMaterial.fill) {
                if (xrayMaterial.fillAlpha < 1.0) {
                    renderFlags.xrayedSilhouetteTransparent = true;
                } else {
                    renderFlags.xrayedSilhouetteOpaque = true;
                }
            }
            if (xrayMaterial.edges) {
                if (xrayMaterial.edgeAlpha < 1.0) {
                    renderFlags.xrayedEdgesTransparent = true;
                } else {
                    renderFlags.xrayedEdgesOpaque = true;
                }
            }
        }
        if (this.numEdgesLayerPortions > 0) {
            const edgeMaterial = this.scene.edgeMaterial._state;
            if (edgeMaterial.edges) {
                renderFlags.edgesOpaque = (this.numTransparentLayerPortions < this.numPortions);
                if (this.numTransparentLayerPortions > 0) {
                    renderFlags.edgesTransparent = true;
                }
            }
        }
        if (this.numSelectedLayerPortions > 0) {
            const selectedMaterial = this.scene.selectedMaterial._state;
            if (selectedMaterial.fill) {
                if (selectedMaterial.fillAlpha < 1.0) {
                    renderFlags.selectedSilhouetteTransparent = true;
                } else {
                    renderFlags.selectedSilhouetteOpaque = true;
                }
            }
            if (selectedMaterial.edges) {
                if (selectedMaterial.edgeAlpha < 1.0) {
                    renderFlags.selectedEdgesTransparent = true;
                } else {
                    renderFlags.selectedEdgesOpaque = true;
                }
            }
        }
        if (this.numHighlightedLayerPortions > 0) {
            const highlightMaterial = this.scene.highlightMaterial._state;
            if (highlightMaterial.fill) {
                if (highlightMaterial.fillAlpha < 1.0) {
                    renderFlags.highlightedSilhouetteTransparent = true;
                } else {
                    renderFlags.highlightedSilhouetteOpaque = true;
                }
            }
            if (highlightMaterial.edges) {
                if (highlightMaterial.edgeAlpha < 1.0) {
                    renderFlags.highlightedEdgesTransparent = true;
                } else {
                    renderFlags.highlightedEdgesOpaque = true;
                }
            }
        }
    }

    // -------------- RENDERING ---------------------------------------------------------------------------------------


    /**
     * @private
     */
    _withEachVisibleLayer(frameCtx, testNumVisibleLayerPortions, cb) {
        if (testNumVisibleLayerPortions && (this.numVisibleLayerPortions === 0)) {
            return;
        }
        const activeSectionPlanes = this.scene._sectionPlanesState.sectionPlanes.filter(p => p.active);
        const testLayerCull = frameCtx.testAABB;
        const renderFlags = this.renderFlags;
        for (let i = 0, len = renderFlags.visibleLayers.length; i < len; i++) {
            const layer = this.layerList[renderFlags.visibleLayers[i]];
            const aabb = layer.getAABB();
            if (((! testLayerCull) || testLayerCull(aabb)) && activeSectionPlanes.every(p => math.planeAABB3Intersect(p.dir, p.dist, aabb) >= 0)) {
                cb(layer);
            }
        }
    }

    drawColorOpaque          (frameCtx) { this._withEachVisibleLayer(frameCtx, false, layer => layer.drawColorOpaque          (this.renderFlags, frameCtx)); }
    drawColorTransparent     (frameCtx) { this._withEachVisibleLayer(frameCtx, false, layer => layer.drawColorTransparent     (this.renderFlags, frameCtx)); }
    drawDepth                (frameCtx) { this._withEachVisibleLayer(frameCtx, false, layer => layer.drawDepth                (this.renderFlags, frameCtx)); } // Dedicated to SAO because it skips transparent objects
    drawSilhouetteXRayed     (frameCtx) { this._withEachVisibleLayer(frameCtx, false, layer => layer.drawSilhouetteXRayed     (this.renderFlags, frameCtx)); }
    drawSilhouetteHighlighted(frameCtx) { this._withEachVisibleLayer(frameCtx, false, layer => layer.drawSilhouetteHighlighted(this.renderFlags, frameCtx)); }
    drawSilhouetteSelected   (frameCtx) { this._withEachVisibleLayer(frameCtx, false, layer => layer.drawSilhouetteSelected   (this.renderFlags, frameCtx)); }
    drawEdgesColorOpaque     (frameCtx) { this._withEachVisibleLayer(frameCtx, false, layer => layer.drawEdgesColorOpaque     (this.renderFlags, frameCtx)); }
    drawEdgesColorTransparent(frameCtx) { this._withEachVisibleLayer(frameCtx, false, layer => layer.drawEdgesColorTransparent(this.renderFlags, frameCtx)); }
    drawEdgesXRayed          (frameCtx) { this._withEachVisibleLayer(frameCtx, false, layer => layer.drawEdgesXRayed          (this.renderFlags, frameCtx)); }
    drawEdgesHighlighted     (frameCtx) { this._withEachVisibleLayer(frameCtx, false, layer => layer.drawEdgesHighlighted     (this.renderFlags, frameCtx)); }
    drawEdgesSelected        (frameCtx) { this._withEachVisibleLayer(frameCtx, false, layer => layer.drawEdgesSelected        (this.renderFlags, frameCtx)); }
    drawOcclusion            (frameCtx) { this._withEachVisibleLayer(frameCtx, true,  layer => layer.drawOcclusion            (this.renderFlags, frameCtx)); }
    drawShadow               (frameCtx) { this._withEachVisibleLayer(frameCtx, true,  layer => layer.drawShadow               (this.renderFlags, frameCtx)); }
    drawPickMesh             (frameCtx) { this._withEachVisibleLayer(frameCtx, true,  layer => layer.drawPickMesh             (this.renderFlags, frameCtx)); }
    drawPickDepths           (frameCtx) { this._withEachVisibleLayer(frameCtx, true,  layer => layer.drawPickDepths           (this.renderFlags, frameCtx)); }
    drawPickNormals          (frameCtx) { this._withEachVisibleLayer(frameCtx, true,  layer => layer.drawPickNormals          (this.renderFlags, frameCtx)); }
    _drawSnap    (frameCtx, isSnapInit) { this._withEachVisibleLayer(frameCtx, true,  layer => layer.drawSnap                 (this.renderFlags, frameCtx, isSnapInit)); }

    drawSnapInit(frameCtx) { this._drawSnap(frameCtx, true ); }
    drawSnap    (frameCtx) { this._drawSnap(frameCtx, false); }

    /**
     * Destroys this SceneModel.
     */
    destroy() {
        Object.values(this._vboLayers).forEach(l => l.destroy());
        this._vboLayers = {};
        this.scene.camera.off(this._onCameraViewMatrix);
        this.scene.off(this._onTick);
        for (let i = 0, len = this.layerList.length; i < len; i++) {
            this.layerList[i].destroy();
        }
        this.layerList = [];
        for (let i = 0, len = this._entityList.length; i < len; i++) {
            this._entityList[i]._destroy();
        }
        this._layersToFinalize = [];
        // Object.entries(this._geometries).forEach(([id, geometry]) => {
        //     geometry.destroy();
        // });
        this._geometries = {};
        this._dtxBuckets = {};
        this._textures = {};
        this._textureSets = {};
        this._meshes = {};
        this._entities = {};
        this.scene._aabbDirty = true;
        if (this._isModel) {
            this.scene._deregisterModel(this);
        }
        super.destroy();
    }
}


/**
 * This function applies two steps to the provided mesh geometry data:
 *
 * - 1st, it reduces its `.positions` to unique positions, thus removing duplicate vertices. It will adjust the `.indices` and `.edgeIndices` array accordingly to the unique `.positions`.
 *
 * - 2nd, it tries to do an optimization called `index rebucketting`
 *
 *   _Rebucketting minimizes the amount of RAM usage for a given mesh geometry by trying do demote its needed index bitness._
 *
 *   - _for 32 bit indices, will try to demote them to 16 bit indices_
 *   - _for 16 bit indices, will try to demote them to 8 bits indices_
 *   - _8 bits indices are kept as-is_
 *
 *   The fact that 32/16/8 bits are needed for indices, depends on the number of maximumm indexable vertices within the mesh geometry: this is, the number of vertices in the mesh geometry.
 *
 * The function returns the same provided input `geometry`, enrichened with the additional key `.preparedBukets`.
 *
 * @param {object} geometry The mesh information containing `.positions`, `.indices`, `.edgeIndices` arrays.
 *
 * @param enableVertexWelding
 * @param enableIndexBucketing
 * @returns {object} The mesh information enrichened with `.buckets` key.
 */
function createDTXBuckets(geometry, enableVertexWelding, enableIndexBucketing) {
    let uniquePositionsCompressed, uniqueIndices, uniqueEdgeIndices;
    if (enableVertexWelding || enableIndexBucketing) { // Expensive - careful!
        [
            uniquePositionsCompressed,
            uniqueIndices,
            uniqueEdgeIndices,
        ] = uniquifyPositions({
            positionsCompressed: geometry.positionsCompressed,
            indices: geometry.indices,
            edgeIndices: geometry.edgeIndices
        });
    } else {
        uniquePositionsCompressed = geometry.positionsCompressed;
        uniqueIndices = geometry.indices;
        uniqueEdgeIndices = geometry.edgeIndices;
    }
    let buckets;
    if (enableIndexBucketing) {
        let numUniquePositions = uniquePositionsCompressed.length / 3;
        buckets = rebucketPositions({
                positionsCompressed: uniquePositionsCompressed,
                indices: uniqueIndices,
                edgeIndices: uniqueEdgeIndices,
            },
            (numUniquePositions > (1 << 16)) ? 16 : 8,
            // true
        );
    } else {
        buckets = [{
            positionsCompressed: uniquePositionsCompressed,
            indices: uniqueIndices,
            edgeIndices: uniqueEdgeIndices,
        }];
    }
    return buckets;
}

function

createGeometryOBB(geometry) {
    geometry.obb = math.OBB3();
    if (geometry.positionsCompressed && geometry.positionsCompressed.length > 0) {
        const localAABB = math.collapseAABB3();
        math.expandAABB3Points3(localAABB, geometry.positionsCompressed);
        geometryCompressionUtils.decompressAABB(localAABB, geometry.positionsDecodeMatrix);
        math.AABB3ToOBB3(localAABB, geometry.obb);
    } else if (geometry.positions && geometry.positions.length > 0) {
        const localAABB = math.collapseAABB3();
        math.expandAABB3Points3(localAABB, geometry.positions);
        math.AABB3ToOBB3(localAABB, geometry.obb);
    } else if (geometry.buckets) {
        const localAABB = math.collapseAABB3();
        for (let i = 0, len = geometry.buckets.length; i < len; i++) {
            const bucket = geometry.buckets[i];
            math.expandAABB3Points3(localAABB, bucket.positionsCompressed);
        }
        geometryCompressionUtils.decompressAABB(localAABB, geometry.positionsDecodeMatrix);
        math.AABB3ToOBB3(localAABB, geometry.obb);
    }
}