Three.js brings 3D graphics to the browser using WebGL. Scene holds all 3D objects, lights, and cameras. Camera defines viewpoint: PerspectiveCamera for realistic view, OrthographicCamera for 2D. Renderer draws scene to canvas: WebGLRenderer for 3D, CSS2DRenderer for overlays. Geometry defines object shape with vertices and faces. Material defines surface appearance: color, texture, reflection. Mesh combines geometry and material into renderable object. Lights illuminate scenes: AmbientLight, DirectionalLight, PointLight. Animations update object properties each frame using requestAnimationFrame. OrbitControls enable mouse-based camera interaction. TextureLoader loads images for material surfaces. GLTFLoader imports 3D models from modeling software. Particle systems create effects like stars and fire. Raycaster detects object intersections with mouse clicks. Shaders provide custom rendering effects. Three.js supports VR and AR through WebXR. Performance optimization uses geometry instancing and LOD. Import maps simplify . Three.js documentation and examples are excellent. 3D web experiences engage users beyond traditional interfaces.
