I need to render a depth pass in mental ray from an orthogonal camera. The Z values need to be distances in world space and in floating point.
I used a SampleInfo node to get the cameraPoint.z value and connected it into a Surface Shader. Everything seems ok expect on one thing. The depth pass I'm getting seem to have some aliasing problems. For example, in a sloped surface (in relation to the camera), the z values should change smoothly, but I get this banding in which consecutive lines have the same Z value! I tried to change all the sampling paramenters in mental ray, but nothing seems to solve! (increasing the number of samples improves a bit, but doesn't solve this problem).
Can you help me on this one?