Skeletal Mesh Optimization

Development Character & Animation
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1

Hello! I have some questions regarding optimization of skeletal meshes.

  1. There is an option for removing bones with the LOD level. How do LOD culled bones compare to simply not having bones there in the first place in terms of performance? Is a simple skeleton and a complex skeleton with LOD culled bones such that they have the same active bones equivalent?

  2. It’s possible to enable and disable materials on different LOD levels. Do disabled materials still incur an additional draw call since they require a material slot? On the Metahuman face mesh, there are multiple material slots solely dedicated to specific LODs. The shader complexity differences seem to be negligible between these materials (Except for a jump at LOD2). If each slot incurs an additional draw call, does anyone know what kind of optimization function these materials perform that would justify the added expense?