I do that for a different reason though.
The dummy bone really defaults to the mesh node.
Some specific animations for example blender will output mesh animations as node animations with no bones, assimp doesn’t see them as mesh animations either, so that’s kind of a problem.
model = modelReader.LoadAsset("AnimatedCube5.fbx");
^^ Is a cube model i made to test for those kinds of node animations.
So i basically make a dummy node to handle it and that entails re-indexing bones so that all the vertice id’s for a mesh with no bones default to id 0 and with a weight of 1 then that automatically points to the dummy node which normally is now set to identity.
When the node animation exists it runs thru its chain and sets that matrix for bone 0 i treat nodes that have mesh names as or indexs to meshes as if they are bone 0, then later draw pushes the bone matrix to the gpu and it blends the vertices with the transform for that bone.
Right now im doing it for each mesh and pushing the bones per mesh to the gpu instead of how i was doing it before with a flat bone list per model. I also now rename the mesh node in the tree to replace the dummybone name with the mesh node name and make a bone with a offset of identity that is linked to the node which is also linked to the mesh and animation node.
I can send you the current version but its still pretty busted up including some of the new methods.