Difference Between Realtime, Mixed, And Baked Lighting in Unity

Yesterday, I touched on how to bake lighting data. Today I will explain the different lighting modes a bit more specifically.

Today’s Objective: Explain the 3 types of lighting modes available in Unity, and the situations they work best in.

Realtime Lighting Mode:

The default of most lights, Realtime lighting is when the lighting effects, like illumination and shadows, are recalculated every frame, leading to accurate lighting but increased processing during runtime.

Realtime lighting also does not deal with Global Illumination (GI) projections, so there will not be any indirect lighting effects seen from realtime lights. Realtime lights do, however, provide good specular lighting when affecting materials.

Baked Lighting Mode:

The opposite of Realtime lighting, Baked lighting is when the lighting effects are not calculated in each frame, but instead calculated at a specified point during development, usually just prior to project release. This lighting data is then combined with the scene render data so that whatever (baked) lighting effects were present at the time of baking, are forever visible in scene regardless of if the light is changed or not.

Baked lighting does contribute to Global Illumination (GI), so indirect lighting is present, but specular lighting suffers instead.

Note: Baked lighting requires one or more lights set to “Baked” mode (or emissive materials), one or more Static (specifically “Contribute GI”. Others are optional) objects, as well as you clicking “Generate Lighting” in the Lighting window.

Mixed Lighting Mode:

Mixed Lighting, as the name suggests, is a mixture between the 2 above lighting modes, aiming to combine the most important parts of both, for situations where the benefits of each are both required.

When selecting all 3 lights, and dragging them, only the Realtime and Mixed update their lighting.