Unified lighting and shadowing

Unified shadow and lighting is the lighting model used in the Doom 3 game developed by Id Software.

Previous 3D games like Quake III, used separate lighting models for determining how a light would illuminate a character or a map. Lighting and shadow information for maps would be static, pre-generated and stored, whereas lighting and shadowing information for characters would be determined at run-time.

Doom 3 uses a unified model that generates the lighting and shadows for everything at run-time. This means that any lights will affect the whole scene and not only certain parts. This may include self-shadowing via shadow volumes, where characters can cast shadows on themselves, for example the shadow cast by the marine's chin onto his neck.

Doom 3 doesn't use OpenGL's built in system, instead, it uses its own system which gives better quality and more accurate illumination than OpenGL's current lighting model.

External links

• OpenGL Lighting Model
• Basic OpenGL Lighting – an explanation of the standard OpenGL lighting by Steve Baker