threejs-lighting

Three.js lighting combines ambient, directional, point, spot, and environment lights to illuminate WebGL scenes. Configure shadow-enabled directional lights and ambient light together to achieve balanced, realistic illumination results quickly.

Directional lights simulate distant sun rays, point lights emit omnidirectionally, spot lights cast cones, and rect area lights define flat illuminated surfaces. Three.js lighting uses these distinct types to match specific physical light sources.

Three.js shadows require enabling shadow maps on the renderer and configuring shadow-enabled lights like directional or spot lights. Adjust shadow camera bounds and bias properties to eliminate artifacts and render accurate silhouettes.

Use environment lighting or image-based lighting (IBL) in Three.js when simulating indirect light reflections on metallic or glossy materials. IBL wraps the scene with an environment map to provide realistic ambient reflections without manual light placement.

Three.js provides light helpers to visually debug and tune light positions, targets, and intensities. Attach helpers to scene lights to see their affected volumes and boundaries, ensuring accurate placement before final rendering.

Using multiple shadow-casting lights in Three.js significantly increases rendering cost and impacts WebGL performance. Limit shadow-enabled lights, prefer baked lighting where possible, and use environment lighting to balance visual fidelity with frame rates.