{
  "$schema": "https://json-schema.org/draft/2020-12/schema",
  "$id": "https://example.com/dsh-3d-model-v1.schema.json",
  "title": "Standardized LLM-readable 3D model document",
  "description": "The single JSON shape every supported 3D source format (OBJ/STL/STEP) is translated into.",
  "type": "object",
  "required": ["schema", "meta", "bounds", "summary", "parts", "analysis"],
  "additionalProperties": false,
  "properties": {
    "schema": { "const": "dsh-3d-model/v1" },
    "meta": {
      "type": "object",
      "required": ["sourceFormat", "units", "generator", "generatedAt"],
      "additionalProperties": false,
      "properties": {
        "sourceFormat": { "enum": ["obj", "stl", "step", "unknown"] },
        "name": { "type": "string" },
        "description": { "type": "string" },
        "units": { "type": "string" },
        "generator": { "type": "string" },
        "generatedAt": { "type": "string", "format": "date-time" }
      }
    },
    "bounds": {
      "type": "object",
      "required": ["min", "max", "size", "center", "radius"],
      "additionalProperties": false,
      "properties": {
        "min": { "$ref": "#/$defs/vec3" },
        "max": { "$ref": "#/$defs/vec3" },
        "size": { "$ref": "#/$defs/vec3" },
        "center": { "$ref": "#/$defs/vec3" },
        "radius": { "type": "number" }
      }
    },
    "summary": {
      "type": "object",
      "required": ["partCount", "vertexCount", "triangleCount", "materialCount"],
      "additionalProperties": false,
      "properties": {
        "partCount": { "type": "integer", "minimum": 0 },
        "vertexCount": { "type": "integer", "minimum": 0 },
        "triangleCount": { "type": "integer", "minimum": 0 },
        "materialCount": { "type": "integer", "minimum": 0 }
      }
    },
    "materials": {
      "type": "array",
      "items": { "$ref": "#/$defs/material" }
    },
    "parts": {
      "type": "array",
      "items": { "$ref": "#/$defs/part" }
    },
    "analysis": { "$ref": "#/$defs/analysis" }
  },
  "$defs": {
    "vec3": {
      "type": "array",
      "minItems": 3,
      "maxItems": 3,
      "items": { "type": "number" }
    },
    "material": {
      "type": "object",
      "required": ["id", "color"],
      "additionalProperties": false,
      "properties": {
        "id": { "type": "string" },
        "name": { "type": "string" },
        "color": { "type": "string", "pattern": "^#[0-9a-fA-F]{6}$" },
        "metalness": { "type": "number", "minimum": 0, "maximum": 1 },
        "roughness": { "type": "number", "minimum": 0, "maximum": 1 },
        "opacity": { "type": "number", "minimum": 0, "maximum": 1 }
      }
    },
    "part": {
      "type": "object",
      "required": ["id", "vertices", "indices"],
      "additionalProperties": false,
      "properties": {
        "id": { "type": "string" },
        "name": { "type": "string" },
        "material": { "type": "string" },
        "vertices": { "type": "array", "items": { "type": "number" } },
        "normals": { "type": "array", "items": { "type": "number" } },
        "indices": { "type": "array", "items": { "type": "integer", "minimum": 0 } }
      }
    },
    "analysis": {
      "type": "object",
      "required": ["partCount", "totalSurfaceArea", "totalVolume", "watertight", "parts", "naturalDescription"],
      "additionalProperties": false,
      "properties": {
        "partCount": { "type": "integer", "minimum": 0 },
        "totalSurfaceArea": { "type": "number", "minimum": 0 },
        "totalVolume": { "type": "number" },
        "watertight": { "type": "boolean" },
        "parts": { "type": "array", "items": { "$ref": "#/$defs/partAnalysis" } },
        "naturalDescription": { "type": "string" }
      }
    },
    "partAnalysis": {
      "type": "object",
      "required": ["surfaceArea", "volume", "watertight", "boundaryEdgeCount", "dimensions", "primitive", "primitiveConfidence"],
      "additionalProperties": false,
      "properties": {
        "surfaceArea": { "type": "number", "minimum": 0 },
        "volume": { "type": "number" },
        "watertight": { "type": "boolean" },
        "boundaryEdgeCount": { "type": "integer", "minimum": 0 },
        "dimensions": { "$ref": "#/$defs/vec3" },
        "primitive": { "enum": ["box", "cylinder", "sphere", "torus", "planar", "freeform"] },
        "primitiveConfidence": { "type": "number", "minimum": 0, "maximum": 1 }
      }
    }
  }
}