OTOY Forums

Okay, I want to render with a specular object (in this case, faery wings that have a glass like texture) but have it render with an alpha channel background. Now, I know that because the light is bouncing around, any 'background' would be warped in the wings, but I am not concerned about that. I just want them to have the transparency effect that you would get. Is there a way to get it to simulate that, without having the fill specular render on them? When I try with specular, it ends up making the wings almost black (because there is no 'background' to reflect in them)

I don't entirely understand your question. There are some settings with effect the way alpha is handled by specular materials. Check out Specular Material->Affect Alpha and Fake Shadows. Also Kernel->Alpha Channel and Keep Environment and Alpha Shadows. In general, the background image will not contribute in any way to the render (incl shadows, reflection, etc). If you need the background to be included in the render, use a HDR map plugged into the Environment node.

Paul

Okay. The setup I have now is basically no background at all, and an HDRI image set up as the lighting. But with it now, and the wings as they are, they appear as black textured glass and no transparency at all. But with a background, they appear as a light blue glass with their texture. I am not sure if it's possible to have them be slightly transparent light blue glass without a background, so no matter what I put in a layer behind them (in photoshop), they will just tint the background a slight blue (as well as the texture) . I tend to render with no background or backdrop at all because it's great for making images with transparency to use for web development, but its hard with this kind of problem. Or if I could make it so the wings themselves end up without transparency, but as if they had a texture behind them.

I would suggest using a Specular material with some opacity rather than a Specular material (which needs something in the background to contribute to the lighting) in this situation.

Paul