Animation

• animation_controller: animates descendant skinned meshes with the referenced animation graph and animation set. the skeleton of the skinned meshes and animations in animation set need to be compatible

• bone, skeleton_ref: is the root bone

• bone: is a bone

• skeleton_ref, mesh_ref, ( material_ref || material ): marks this mesh as skinned with the referenced skeleton

• animation_sequence_controller: an instance of an animation sequence with entities set to its tracks