Grimrock

Flatline,
Very cool. Can't wait to see it. And nice solution, that is easier than I was thinking.

The night brought some idea and I fear the thing might be that the monsters require a skeletal animation while the model has no skeleton nodes, so it's animated through traditional techniques of changing its matrix. I really don't know, but I'm guessing

The solution with two models would probably work due to some odd behaviour I noticed when trying to attach the deamonhead to the basic uggardian animation (as suggested by Phitt): if a node is not specified in animation, its mesh is rendered with the model matrix, while the node specified in "meshName" (which must be a mesh) is not rendered if it does not have bones. However this solution would spam the console of warnings that the model has not a valid skeleton, so it seems that the real solution to this is really adding a dummy single bone which tricks the engine in performing traditional animation. This needs some changes to the anim editor or GMT, I will try to experiment with it but no guarantees

If I sound confused, it's because I am