I’ve been fighting this issue with almost every project I do with yafray. I want to render my model with nice reflections. For reflections I use either environment map as world texture or real objects.
But. I don’t want the ugly environment to show up in the render. So I’ve been using background planes. But what if I want to have clean alpha in my render? Or I need to spin the camera around the object? I could always parent the background plane to camera but that is a bit silly… And that of course loses the alpha. Is there a better way of doing this?
With blender internal things are better (there is the env-button for objects). But also with blender internal the environment map affects how the alpha is premultiplied and that causes problems.
This time I’m trying to render a car with white background and environment reflections (fake studio lighting so there are only planes around the car).
Also if you know how to go around this issue with render layers / compositing please share your wisdom.
In 3ds max there is the matte material option for background planes… It renders with full alpha premultiplied with black. I miss that feature.