zdepth with opacity mapped geometry

Who knows a trick for rendering frames that give zdepth information with opacity mapped geometry?
I have some objects that look like clouds, camera facing planes with opacity. I want to try and create some sort of zdepth pass for post work.

any ideas?

You need to turn filtering ON for the depth map. It will make the opacity correct but the depth map will be antialiased though so the edges get screwed up. Not sure if there’s any other way.

It CAN be done!!

Have a look at this post regarding your issue…went through it recently

Cheers

http://www.chaosgroup.com/forums/vbulletin/showthread.php?48712-very-frustrating-limitations-of-the-Vray-Z-depth-buffer.