thanks for your help. However I've been investigating a little bit on the subject and here is what I could find out.

First of all, After effects CAN handle the zbuffer in RLA files (through 3d channel extract, depth of field and other plugins that come in standard with 5.5 pro bundle version). BUT ! (yes there is a but) the only problem is that it only handles RLA files coming from 3ds max.

RLA file format is formerly from Alias Wavefront (done in 1991). However when 3ds max got released, Discreet put their nose into it and "enhanced" it (actually "modified" is the word) with gbuffers support. Eventually the old file format isn't recognized by common apps and they only support the new modified format which is incompatible with the old one except for the rgb and alpha channels which are still properly handled.

We're now writing a converter to convert the wavefront RLA to make them compatible discreet RLA.

If any of you is interested by this little tool. Just drop in a note and we'll publish it here !

Cheers:banana: