Hi there. I'm using maya 2010 and am having some difficulty with the shadow pass feature in mental ray...I know, I know...old news.
I've set up a ground plane and a wall both with a 'use background' shader a spaceship model that flies past creating a shadow on both (created by a directional light with 'use ray trace shadows on').
The problem is when I come to render my passes. The beauty pass can see the shadows and they even show up in the render preview alpha channel but in the shadow channel it doesn't seem to be picking them up, all I can see is a black image.
At first I thought that it was hidden in a different channel but I had a look in photoshop and After effects but the alpha channel is completely white. Where have my shadows gone? It must be something in the render globals.
I've looked at a lot of forum so far and have found no answers, please help