If you have come this far you might be interested in a couple of small tips and tricks on how to get that 32-bit floating point depth channel to render out of V-Ray and into Nuke, similar to what you might be used to from Mental Ray and the IFF file format.
Table of contents
- Creating a V-Ray Z-depth pass in Maya
- Bringing the V-Ray Z-depth pass into Nuke
Creating a V-Ray Z-depth pass in Maya
Render settings
Open up the render settings, go to the V-Ray tab and make sure that Image format is set to OpenEXR (multichannel) and that OpenEXR data type is set to 32-bit float.
Now go to the Render Elements tab, enable V-Ray Render Elements and Multi-channel EXR. Add the ZDepth render element. The default settings should be fine.
Z-depth in Nuke
Load the EXR file (containing the Z-depth pass) into Nuke using the Read node. Now, view the Z channel in the viewer. You will see an entirely black image!
This is because V-Ray stores its Z-depth in a different manner from Mental Ray. In Nuke, create a ZDepth node and connect its Input to your Read node. The result should look like the image above.
Now you should be able to see a grayscale Z-depth pass! You can then adjust the black and white point of the Z-depth pass.
This is a quick and dirty way to work with Z-depth in Nuke. For a more robust workflow, you can use the VrayZDepth node from rv-nodes (which is a collection of various Nuke nodes written by different artists and can be found on Nukepedia).