I split up the mesh into subsets. The final product as 116 subsets, I notice 2 or more faces could be merged into one subset, and render in one batch. How do I control the Material IDs,

The scenario is I need to create 116 materials as after-product if there is 116 subsets generated.

I look up the material by the attribute table's attribId, but the ids scatter around, for example, the first subset attrib id is 0 and the next is 60

Should I make up another level of lookups, say attrib id 0 and 60 goes to material slot 0 and atrrib id 1,2,3,61  go to slot 1?

https://www.mvps.org/directx/articles/mesh_subset.htm

The picture shows everybody maps to subset 0

The function still returns 116 subsets rather than 1

Thanks

Jack