In case you missed Francois Tarlier’s newest Pixel Bender offerings for After Effects that are available at AEscripts, they are quite notworthy!
The PPass plugin for After Effects will create mattes that are attached to objects in 3D renders by using a PPass (also called point pass, position pass or position point pass). Up to this point, this kind of thing was only available in Nuke, but with ft-PPass2Matte the same thing can be achieved in After Effects. This will allow you to create custom mattes in After Effects without having to go back to the 3D program to generate them.
The other plugin of note is the ft-UVPass Pixel Bender Plug for After Effects. This plugin will use a “UV pass” (or ST map) rendered from your 3D package to directly re-texture your objects in After Effects, sweet and sweet, because both of these are long overdue in After Effects.
ft-UVPass Demo
ft-PPass2Matte Demo