Post
Pre-computed lighting stored in lightmaps and textures, saving runtime cost at the price of dynamic flexibility.
Real-time global illumination is expensive. Baked lighting pre-computes how light bounces through a static scene and stores the result as textures (lightmaps) or volumes. At runtime, the engine just samples them. The tradeoff is that anything baked cannot change: move a wall and the shadow stays where it was. Modern engines like UE5's Lumen reduce the need for baking, but baking remains the workhorse for mobile and last-gen console ports.
Example
Half-Life 2 used baked lightmaps to stunning effect in 2004. Most of Nintendo's first-party games still rely heavily on baked lighting for performance. UE5's Lumen provides real-time alternative but teams often still bake for perf wins on low-end platforms.
Why it matters
Baked lighting is the original workhorse of 3D graphics, and even with real-time GI on the rise, most games still use some form of baking. Understanding it explains engine choices, build times, and why some games look stunning but have static lighting.
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