Who knows, this may belong in the AE Basics forum but I happen to be working with Particular and Form today. I have several layers I created in separate comps then after I got them to look perfect I put them in a master comp. It wasn't until after I added the camera that I notice it was a postcard. Is that a Trapcode or AE thing? I'll just copy and paste the individual layers so its fixed. Is there a way to make the layers of a nested comp 3d?
You cant precomp particular and then turn on the collapse transform and expect it to return to true 3d. Particular does not work that way. In order for it to interact with 3d, Particular must be applied to a layer in that comp.