I have a problem using trapcode Particular and Form in the same composition ... The emitter of Particular is a light and goes from the front to the back of the composition through Z axis. The particles of the form are in the middle of this travel. What I can not do is that when the particles of the particular effect are established to be at the back of the form they always look forward ... I tried to solve it selecting an obscuration layer in the particular settings but it tells me that only serve with the 3d layers activated an this layer cannot be activated because the form effects do not work with 3d layers. I don't have any other idea!!
I hope someone knows a way to solve this! Hopefully!
I don't quite see your problem. Since they are strictly 2D layers, you can just re-arrange them. If you need more complex setups and sandwich stuff inbetween, simply use duplicates and make use of the internal depth range controls or use conventional matting techniques to mutually cut out regions. The rest is of no interest - since AE does not provide a consistent 3D space, different 3D effects never interact. Inherent limitation.
Form and Particular can interact with your 3D camera but can't have true 3D integration. They'll always be in front of every layer that are below them in your layer stack.
I've developed a script to workaround this issue, maybe it can help you: http://www.aescripts.com/sparticular
Hope that helps