I'm currently trying to build a way to attach a second rig to my character rig so that I can animate both the attachment and the character at the same time. I tried to pass in the second rigs skeleton to my main rigs hda so that I could run a Rig Attribute Vop to parent constrain the root bone of my attachment rig to the character rig but it makes the character rig blow up.

I also tried another idea which was to import the mesh and rig of the attachment into the character rig and merge the mesh and bones of the attachment rig to the character rig. This also broke the deformation of the character rig.

Is there any way to do this currently?