I’ve recently found a performance issue when parenting whole objects to bones in Blender.
If you parent many high polygon objects to bones in Blender using the Ctrl-P > Bone or Ctrl-P > Bone Relative command then you get a large performance hit while running in Unity.
However if you leave the objects unparented in Blender and instead change the objects’ parent to the bones in the Unity editor then the performance is much better, even though the end result is the same.
I’m guessing the issue is when Unity is importing these parented objects it’s using individual vertex transformations to map the object to the bone rather than just parenting the entire object.
Maybe this is how Blender stores parented objects so is unavoidable, but I thought I’d raise the issue in case it can be fixed to avoid superfluous vertex transformations.
I think it’s more likely they’re being interpreted as submeshes due to how blender is exporting them, which means multiple skinning operations are taking place. Check that by pausing the game and investigating.
The end result is most certainly not the same, two different things are occurring.
Check the SkinnedMeshRenderer. If you have more than one material assigned by default, then you have several submeshes.
If you want to be really sure, try to assign several materials. If you only have one submesh, Unity will complain that you have more materials then submeshes.