Photoshop actions are pretty awesome. They have limitations though, and I ran into this when trying to do a fairly simple task... automatically renaming a Photoshop group layer to the source files name, sans extension. Here's an overview of that scenario and how I did it.
If you found this page, it is likely because you are frustrated that Adobe took away the direct ability to export a 3D model from inside a 3D PDF. Here are some alternate paths you can take.