Objects can be baked on per-vertex level instead of having textures, if they or their parent have a Lightmap Group Selector component with a Lightmap Group asset set to Vertex mode.
Vertex lightmaps are compatible with shadowmasks, as well as Dominant Direction and SH modes.
There are pros and cons using vertex baking.
- No UVs needed. Suitable for complex geometry that is impossible to unwrap well.
- No space wasted - padding and empty spaces in the lightmap are not a problem.
- Obviously vertex interpolation is less subtle than texel interpolation.
- Normal texture compression techniques do not apply.
- Modified shader needed (Bakery includes such shaders).
- Denoising is not applied.
The data is stored in following vertex attributes:
- Mesh.colors stores the color lightmap (or first coefficient of the SH lightmap).
- Mesh.uv2 can store packed dominant direction, shadowmask and part of SH data.
- Mesh.uv3 can store additional SH data.