WebGLRenderer

WebGLRenderer is a rendering engine component of the Three.js library that uses WebGL to draw 3D scenes in a web browser. It translates a scene graph, a camera, and materials into pixels on a canvas, supporting features such as lighting, shading, textures, and post-processing effects.

WebGLRenderer manages WebGL state, compiles and binds shaders, and implements the rendering pipeline for a variety of material models (including physically based materials). It supports lights, shadows, fog, and texture mapping, and it can render to on-screen canvases or to offscreen render targets for effects pipelines.

Technically, the renderer runs atop WebGL (WebGL 1 or WebGL 2, depending on browser support). It exposes a capabilities object that reports supported features and limits, and it can query extensions. It also provides options such as antialias, alpha, and preserveDrawingBuffer to tailor rendering behaviour.

Usage involves creating an instance, configuring size and pixel ratio, and invoking render with a scene and a camera in an animation loop. It also supports rendering to render targets for post-processing via systems like EffectComposer, and can be reset or resized as needed.

Limitations include reliance on browser WebGL support and hardware capabilities, potential performance costs on mobile devices, and memory management considerations. WebGLRenderer is typically used within Three.js projects but can be understood as the standard GPU-based renderer for web-based 3D scenes.