Animation BlendShape
 

Hi, I'm new in this Forum, and I would need help you.
I'm developing a game with unity, and I tried to use some utility like Brekel for tracking the facial expression.
I found a script to create a blendshape with my facial expression animation, so I have 3 "heads" animated that I connected like a simple blendshape.
Probably it's wrong, but is the only method pratical for me in this moment.
In Unity there isn't a problem, but in Maya I must create an animation with the same blendshape.

The question is, have someone tried to use blendshape (in Maya) that are already animated?

If I start the single blenshape it's Ok, but when I put the blendshapes in sequence I had a problem.
My problem is that when I put a keyframe to start my animated blendshape, the second blendshape that must start is blocked (like if it hadn't an animation). So, what's the problem?

I know that is quite strange, If you have a best solution let me know! ;)
Thanks, Lara