Maya :: How To Load A Model Using Trax

I'm having a lot of problems trying to load a model I animated using Trax.

First I modeled and rigged a character in Maya and saved it as model.mb.

Next I created an empty file and referenced my model file into in. In the new file I created a character set based on all the rig handles. Next I spent a few hours animating some simple walk cycles and jumps, putting each animation into a separate Trax track. I also created a few character poses.

Last night, everything was working fine. I could select poses and apply them. I could enable single Trax tracks and play them and everything went smoothly. I saved and closed my file.

Today when I opened the file and tried to continue, none of the Trax animations I saved were working. When I try to assume a pose, the rigging moves seemingly random directions. When I enable a Trax clip and play it, the animation is all messed up.

I experimented today with a simple test file. I created a new empty file, referenced in my model, created a character set and a few character poses. Everything was working fine. I could select the bind poses in the visor and assume whatever pose I wanted without error. Then I saved the file and closed it. When I reopened the file and tried to assume the same poses, my character's limbs shot off in all sorts of weird directions.

What's going on? Have I lost my work? How am I supposed to use Trax is if this happens if I simply save, close and reopen Maya?

(The rigging was all nurbs curves with a little bit of Set Driven Keys for the fingers and feet. I also hid and locked attributes of the nurbs I wasn't using. The rigging mostly done using constraints, although I also used straight parenting for some IK handles.)