The bind-group index §59's packed metallic-roughness map occupies when
the albedo map is also bound: group 3, the last WebGPU slot. An
mr-only draw binds the same layout object at
SHADED_MAP_BIND_GROUP_INDEX instead — see the module header.
Distinct from WebGL's METAL_ROUGHNESS_TEXTURE_UNIT (a texture unit,
not a bind-group index).
The bind-group index §59's packed metallic-roughness map occupies when the albedo
mapis also bound: group 3, the last WebGPU slot. An mr-only draw binds the same layout object at SHADED_MAP_BIND_GROUP_INDEX instead — see the module header. Distinct from WebGL'sMETAL_ROUGHNESS_TEXTURE_UNIT(a texture unit, not a bind-group index).