Ztransp and z-depth

Hello everyone,

I’m having problems making the z-depth or mist pass, because they don’t take care of z-transp materials. and for my scene is necessary because is plenty of grass and trees with leaves.
I have being reading this thread http://blenderartists.org/forum/showthread.php?t=120889 which is really interesting, but even with the solutions proposed I can’t fix it.

I’m be very glad if you could help me, here you have a simple blend file showing the problem.



ztransp.blend (365 KB)

I’m finding your file hard to follow… little more explanation? All I see is a cube and a sphere over a spotlight background.

By the sounds of it, you’d need to add / multiply / maybe invert etc a pass of the alpha areas over the top of the actual z-pass. The blur is done in post, so it’s a matter of patching the initial grey scale z-pass image.

Thanks for the replay,

In the scene there are 3 grids which have the material with ztransp, if you edit the material and change the alpha value to 1 you’ll see that now mist pass will detect three grids, but obviously, without transparency: that’s the strange thing. mist pass and z-depth don’t detect transparent objects.


Finally I have found where the problem was. I have fix it turning on combined in renderLayers tab. It’s very strange thing, but this has fixed it.

Here is the fixed blend file.


ztranspFixed.blend (365 KB)

Glad you got it sorted. Unfortunately, while the blend file is “packed” nothing but a black render for me here.


I don’t know if you load the interface, if you don’t, you must go to node editor and click in the button re-render this layer, then you should see the image in the backdrop.

Hope this works :wink: