Three.js is a mature, production-grade JavaScript 3D library providing WebGL and WebGPU renderers, a comprehensive scene graph, and extensive tooling for 3D web applications. The codebase demonstrates exceptional architecture with a clean separation between core rendering (src/), the new node-based shader system TSL (Three.js Shading Language), and a vast ecosystem of addons in examples/jsm/. The library supports multiple renderers (WebGLRenderer, WebGPURenderer, CSS2DRenderer, CSS3DRenderer, SVGRenderer), a full animation system, physics integrations (Ammo, Rapier, Jolt), WebXR for AR/VR, and loaders for 30+ formats (GLTF, FBX, USD, OBJ, etc.). The TSL node system is a standout achievement - a compiler-like architecture that transpiles shader graphs to GLSL/WGSL with automatic differentiation, lighting models, and post-processing. The WebGPU backend shows deep GPU API expertise with pipeline management, bind groups, and descriptor reuse. Code quality is consistently high with strong typing patterns, comprehensive unit tests (200+ test files), and modern ES module architecture. The project is actively maintained with recent commits, semantic versioning, and CI/CD pipelines.
This is a monorepo centered on `@google/model-viewer`, a production web component that renders glTF/GLB 3D models in the browser using Three.js and Lit. The core package provides a `<model-viewer>` custom element with a rich feature surface: WebXR/Scene Viewer/Quick Look AR, animation controls, camera orbit/perspective controls, environment lighting, hotspots/annotations, a mutable scene-graph API, lazy loading, and post-processing via a companion `model-viewer-effects` package. In addition to the library itself, the repo contains `space-opera`, a Redux + Lit-based interactive editor for configuring model-viewer snippets and editing glTF materials, plus a full documentation/examples site and render-fidelity tooling that performs golden-image screenshot comparisons across renderers. Although the dominant character is an application/library monorepo, it also includes research-grade visual fidelity workflows and color science work around tone mapping.