--- name: three-best-practices description: Three.js performance optimization and best practices guidelines. Use when writing, reviewing, or optimizing Three.js code. Triggers on tasks involving 3D scenes, WebGL/WebGPU rendering, geometries, materials, textures, lighting, shaders, or TSL. license: MIT metadata: author: three-agent-skills version: "2.1.0" three-version: "0.182.0+" --- # Three.js Best Practices Comprehensive performance optimization guide for Three.js applications. Contains 120+ rules across 18 categories, prioritized by impact. ## Sources & Credits > This skill compiles best practices from multiple authoritative sources: > - Official guidelines from Three.js `llms` branch maintained by [mrdoob](https://github.com/mrdoob) > - [100 Three.js Tips](https://www.utsubo.com/blog/threejs-best-practices-100-tips) by [Utsubo](https://www.utsubo.com) - Excellent comprehensive guide covering WebGPU, asset optimization, and performance tips ## When to Apply Reference these guidelines when: - Setting up a new Three.js project - Writing or reviewing Three.js code - Optimizing performance or fixing memory leaks - Working with custom shaders (GLSL or TSL) - Implementing WebGPU features - Building VR/AR experiences with WebXR - Integrating physics engines - Optimizing for mobile devices ## Rule Categories by Priority | Priority | Category | Impact | Prefix | |----------|----------|--------|--------| | 0 | Modern Setup & Imports | FUNDAMENTAL | `setup-` | | 1 | Memory Management & Dispose | CRITICAL | `memory-` | | 2 | Render Loop Optimization | CRITICAL | `render-` | | 3 | Draw Call Optimization | CRITICAL | `drawcall-` | | 4 | Geometry & Buffer Management | HIGH | `geometry-` | | 5 | Material & Texture Optimization | HIGH | `material-` | | 6 | Asset Compression | HIGH | `asset-` | | 7 | Lighting & Shadows | MEDIUM-HIGH | `lighting-` | | 8 | Scene Graph Organization | MEDIUM | `scene-` | | 9 | Shader Best Practices (GLSL) | MEDIUM | `shader-` | | 10 | TSL (Three.js Shading Language) | MEDIUM | `tsl-` | | 11 | WebGPU Renderer | MEDIUM | `webgpu-` | | 12 | Loading & Assets | MEDIUM | `loading-` | | 13 | Core Web Vitals | MEDIUM-HIGH | `vitals-` | | 14 | Camera & Controls | LOW-MEDIUM | `camera-` | | 15 | Animation System | MEDIUM | `animation-` | | 16 | Physics Integration | MEDIUM | `physics-` | | 17 | WebXR / VR / AR | MEDIUM | `webxr-` | | 18 | Audio | LOW-MEDIUM | `audio-` | | 19 | Post-Processing | MEDIUM | `postpro-` | | 20 | Mobile Optimization | HIGH | `mobile-` | | 21 | Production | HIGH | `error-`, `migration-` | | 22 | Debug & DevTools | LOW | `debug-` | ## Quick Reference ### 0. Modern Setup (FUNDAMENTAL) - `setup-use-import-maps` - Use Import Maps, not old CDN scripts - `setup-choose-renderer` - WebGLRenderer (default) vs WebGPURenderer (TSL/compute) - `setup-animation-loop` - Use `renderer.setAnimationLoop()` not manual RAF - `setup-basic-scene-template` - Complete modern scene template ### 1. Memory Management (CRITICAL) - `memory-dispose-geometry` - Always dispose geometries - `memory-dispose-material` - Always dispose materials and textures - `memory-dispose-textures` - Dispose dynamically created textures - `memory-dispose-render-targets` - Always dispose WebGLRenderTarget - `memory-dispose-recursive` - Use recursive disposal for hierarchies - `memory-dispose-on-unmount` - Dispose in React cleanup/unmount - `memory-renderer-dispose` - Dispose renderer when destroying view - `memory-reuse-objects` - Reuse geometries and materials ### 2. Render Loop (CRITICAL) - `render-single-raf` - Single requestAnimationFrame loop - `render-conditional` - Render on demand for static scenes - `render-delta-time` - Use delta time for animations - `render-avoid-allocations` - Never allocate in render loop - `render-cache-computations` - Cache expensive computations - `render-frustum-culling` - Enable frustum culling - `render-update-matrix-manual` - Disable auto matrix updates for static objects - `render-pixel-ratio` - Limit pixel ratio to 2 - `render-antialias-wisely` - Use antialiasing judiciously ### 3. Draw Call Optimization (CRITICAL) - `draw-call-optimization` - Target under 100 draw calls per frame - `geometry-instanced-mesh` - Use InstancedMesh for identical objects - `geometry-batched-mesh` - Use BatchedMesh for varied geometries (same material) - `geometry-merge-static` - Merge static geometries with BufferGeometryUtils ### 4. Geometry (HIGH) - `geometry-buffer-geometry` - Always use BufferGeometry - `geometry-merge-static` - Merge static geometries - `geometry-instanced-mesh` - Use InstancedMesh for identical objects - `geometry-lod` - Use Level of Detail for complex models - `geometry-index-buffer` - Use indexed geometry - `geometry-vertex-count` - Minimize vertex count - `geometry-attributes-typed` - Use appropriate typed arrays - `geometry-interleaved` - Consider interleaved buffers ### 5. Materials & Textures (HIGH) - `material-reuse` - Reuse materials across meshes - `material-simplest-sufficient` - Use simplest material that works - `material-texture-size-power-of-two` - Power-of-two texture dimensions - `material-texture-compression` - Use compressed textures (KTX2/Basis) - `material-texture-mipmaps` - Enable mipmaps appropriately - `material-texture-anisotropy` - Use anisotropic filtering for floors - `material-texture-atlas` - Use texture atlases - `material-avoid-transparency` - Minimize transparent materials - `material-onbeforecompile` - Use onBeforeCompile for shader mods (or TSL) ### 6. Asset Compression (HIGH) - `asset-compression` - Draco, Meshopt, KTX2 compression guide - `asset-draco` - 90-95% geometry size reduction - `asset-ktx2` - GPU-compressed textures (UASTC vs ETC1S) - `asset-meshopt` - Alternative to Draco with faster decompression - `asset-lod` - Level of Detail for 30-40% frame rate improvement ### 7. Lighting & Shadows (MEDIUM-HIGH) - `lighting-limit-lights` - Limit to 3 or fewer active lights - `lighting-shadows-advanced` - PointLight cost, CSM, fake shadows - `lighting-bake-static` - Bake lighting for static scenes - `lighting-shadow-camera-tight` - Fit shadow camera tightly - `lighting-shadow-map-size` - Choose appropriate shadow resolution (512-4096) - `lighting-shadow-selective` - Enable shadows selectively - `lighting-shadow-cascade` - Use CSM for large scenes - `lighting-shadow-auto-update` - Disable autoUpdate for static scenes - `lighting-probe` - Use Light Probes - `lighting-environment` - Environment maps for ambient light - `lighting-fake-shadows` - Gradient planes for budget contact shadows ### 8. Scene Graph (MEDIUM) - `scene-group-objects` - Use Groups for organization - `scene-layers` - Use Layers for selective rendering - `scene-visible-toggle` - Use visible flag, not add/remove - `scene-flatten-static` - Flatten static hierarchies - `scene-name-objects` - Name objects for debugging - `object-pooling` - Reuse objects instead of create/destroy ### 9. Shaders GLSL (MEDIUM) - `shader-precision` - Use mediump for mobile (~2x faster) - `shader-mobile` - Mobile-specific optimizations (varyings, branching) - `shader-avoid-branching` - Replace conditionals with mix/step - `shader-precompute-cpu` - Precompute on CPU - `shader-avoid-discard` - Avoid discard, use alphaTest - `shader-texture-lod` - Use textureLod for known mip levels - `shader-uniform-arrays` - Prefer uniform arrays - `shader-varying-interpolation` - Limit varyings to 3 for mobile - `shader-pack-data` - Pack data into RGBA channels - `shader-chunk-injection` - Use Three.js shader chunks ### 10. TSL - Three.js Shading Language (MEDIUM) - `tsl-why-use` - Use TSL instead of onBeforeCompile - `tsl-setup-webgpu` - WebGPU setup for TSL - `tsl-complete-reference` - Full TSL type system and functions - `tsl-material-slots` - Material node properties reference - `tsl-node-materials` - Use NodeMaterial classes - `tsl-basic-operations` - Types, operations, swizzling - `tsl-functions` - Creating TSL functions with Fn() - `tsl-conditionals` - If, select, loops in TSL - `tsl-textures` - Textures and triplanar mapping - `tsl-noise` - Built-in noise functions (mx_noise_float, mx_fractal_noise) - `tsl-post-processing` - bloom, blur, dof, ao - `tsl-compute-shaders` - GPGPU and compute operations - `tsl-glsl-to-tsl` - GLSL to TSL translation ### 11. WebGPU Renderer (MEDIUM) - `webgpu-renderer` - Setup, browser support, migration guide - `webgpu-render-async` - Use renderAsync for compute-heavy scenes - `webgpu-feature-detection` - Check adapter features - `webgpu-instanced-array` - GPU-persistent buffers - `webgpu-storage-textures` - Read-write compute textures - `webgpu-workgroup-memory` - Shared memory (10-100x faster) - `webgpu-indirect-draws` - GPU-driven rendering ### 12. Loading & Assets (MEDIUM) - `loading-draco-compression` - Use Draco for large meshes - `loading-gltf-preferred` - Use glTF format - `gltf-loading-optimization` - Full loader setup with DRACO/Meshopt/KTX2 - `loading-progress-feedback` - Show loading progress - `loading-async-await` - Use async/await for loading - `loading-lazy` - Lazy load non-critical assets - `loading-cache-assets` - Enable caching - `loading-dispose-unused` - Unload unused assets ### 13. Core Web Vitals (MEDIUM-HIGH) - `core-web-vitals` - LCP, FID, CLS optimization for 3D - `vitals-lazy-load` - Lazy load 3D below the fold with IntersectionObserver - `vitals-code-split` - Dynamic import Three.js modules - `vitals-preload` - Preload critical assets with link tags - `vitals-progressive-loading` - Low-res to high-res progressive load - `vitals-placeholders` - Show placeholder geometry during load - `vitals-web-workers` - Offload heavy work to workers - `vitals-streaming` - Stream large scenes by chunks ### 14. Camera & Controls (LOW-MEDIUM) - `camera-near-far` - Set tight near/far planes - `camera-fov` - Choose appropriate FOV - `camera-controls-damping` - Use damping for smooth controls - `camera-resize-handler` - Handle resize properly - `camera-orbit-limits` - Set orbit control limits ### 15. Animation (MEDIUM) - `animation-system` - AnimationMixer, blending, morph targets, skeletal ### 16. Physics (MEDIUM) - `physics-integration` - Rapier, Cannon-es integration patterns - `physics-compute-shaders` - GPU physics with compute shaders ### 17. WebXR (MEDIUM) - `webxr-setup` - VR/AR buttons, controllers, hit testing ### 18. Audio (LOW-MEDIUM) - `audio-spatial` - PositionalAudio, HRTF, spatial sound ### 19. Post-Processing (MEDIUM) - `postprocessing-optimization` - pmndrs/postprocessing guide - `postpro-renderer-config` - Disable AA, stencil, depth for post - `postpro-merge-effects` - Combine effects in single pass - `postpro-selective-bloom` - Selective bloom for performance - `postpro-resolution-scaling` - Half resolution for 2x FPS - `postpro-webgpu-native` - TSL-based post for WebGPU ### 20. Optimization (HIGH) - `mobile-optimization` - Mobile-specific optimizations and checklist - `raycasting-optimization` - BVH, layers, GPU picking ### 21. Production (HIGH) - `error-handling-recovery` - WebGL context loss and recovery - `migration-checklist` - Breaking changes by version ### 22. Debug & DevTools (LOW) - `debug-devtools` - Complete debugging toolkit - `debug-stats-gl` - stats-gl for WebGL/WebGPU monitoring - `debug-lil-gui` - lil-gui for live parameter tweaking - `debug-spector` - Spector.js for WebGL frame capture - `debug-renderer-info` - Monitor draw calls and memory - `debug-three-mesh-bvh` - Fast raycasting with BVH - `debug-context-lost` - Handle WebGL context loss - `debug-animation-loop-profiling` - Profile render loop sections - `debug-conditional` - Remove debug code in production ## How to Use Read individual rule files for detailed explanations and code examples: ``` rules/setup-use-import-maps.md rules/memory-dispose-geometry.md rules/tsl-complete-reference.md rules/mobile-optimization.md ``` Each rule file contains: - Brief explanation of why it matters - BAD code example with explanation - GOOD code example with explanation - Additional context and references ## Key Patterns ### Modern Import Maps ```html ``` ### Proper Disposal ```javascript function disposeObject(obj) { if (obj.geometry) obj.geometry.dispose(); if (obj.material) { if (Array.isArray(obj.material)) { obj.material.forEach(m => m.dispose()); } else { obj.material.dispose(); } } } ``` ### TSL Basic Usage ```javascript import { texture, uv, color, time, sin } from 'three/tsl'; const material = new THREE.MeshStandardNodeMaterial(); material.colorNode = texture(map).mul(color(0xff0000)); material.colorNode = color(0x00ff00).mul(sin(time).mul(0.5).add(0.5)); ``` ### Mobile Detection ```javascript const isMobile = /Android|iPhone|iPad|iPod/i.test(navigator.userAgent); renderer.setPixelRatio(Math.min(window.devicePixelRatio, isMobile ? 1.5 : 2)); ```