Lewis Young shares his tool for Visualizing a Depth Pass in Maya called “Friendly Depth”, which he describes as “a depth shader without the pain”. Friendly Depth for Maya will allow you to view what your depth pass will look like in realtime showing clipping values and falloff right in the Maya viewport, for any camera, and any render engine.
A depth shader without the pain. View in realtime and render with any engine. No measuring, no render testing, no mel scripts.
The tool works rather cleverly with nodes; By using a 3D texture that can be seen in realtime right in the viewport and is connected to the depth values when rendering Friendly Depth doesn’t use a complicated MEL script to do what it does.
With Friendly Depth, simply select the 3D texture and parent it to the camera you are rendering from and adjust its scale to set the range. Check out Friendly Depth, a solution for visualising and rendering depth passes in Maya here.