I output all my still images for catalog as tifs with an alpha channel. I have a scene that has a surf wall in the background so FG has an environment to bounce some light off of. Is there a way to have the surf wall effect the environment, even reflect in my shiny materials, but not render in the background of the image?
The reason I ask this is because right now I have to render one image with the surf wall to get the lighting I want, and another without the surf wall to get my alpha channel. ...Just trying to avoid the double renders.
Max Design 2014 / Win 7 Pro
Xeon E5-2687W @ 3.10 GHz (x2); 64 GB Ram; Nvidea 4000 and GTX 570
Use the environment/Background Raytype Switcher. This will let you have one colour/map for the background and another for the environment - lighting and reflections. If you are using a Background plane for reflections, use the Matte/Shadow/Reflection Shader with Environment/Background Camera Map.
For more detail look up mr Production Shaders. There is a PDF with Max and a Few topics in this forum.