Matte Shadow material Vray problem
How can Extract the shadow information on a separate channel???
The answer is matte shadow material. BUT althrough the scanline renderer works fine, the Vray renderer does NOT the job properlly.
1. a simple box, plane and spot light (for cast shadows) scene in max
2. Max scanline render with standard material for plane
3. Scanline render with matte/shadow material for the plane
4. The alpha mask for the image (scanline render)
5. The alpha mask for the image rendered with vray
Vray consider also the plane as a object and do not treat corectlly the matte shadow material applied.
download the scene (right click - save target as..) matteshadow.max