I do a lot of animating of scanned greeting cards and invitations that involve multiple folds opening up to show the inside. Right now, I do it the labor-intensive way, creating an inside and outside layer for each piece of the card and then separately animating the inside and outside for each motion of the card as it folds open. Could someone tell me how to generate a 3d object in After Effects or Photoshop that has a front and back so I could just animate each piece of the card instead of having to animate two sides for each segment?
Michael is correct. Of course, even in the 3D world, you still have to have two graphics, one for each side, then map them to the planes for front and back.
I know that there's an expression that will make the object facing the camera invisible once it turns away from the camera, but that's sort of complicating the process. If you want more detail on Michael's solution, look here: