OTOY Forums

I have some product rotations that I have animated with the alpha channel on so that video compositors can put the animations on their own backgrounds (most likely black) as part of a bigger video production. However, the scenes are using HDRI environments to get nice reflections off the products. I have "Keep Environment" turned off. The only problem with is that it looks like the edges are anti-aliased against the bright HDRI environment, but if the products will appear on a black background there will be fuzzy light edges around them. If I change the HDRI environment to something dark then the products will appear darker than I would like. What do Octane users generally do in this situation? I don't see any anti-aliasing settings in Octane. Any recommendations?

I am rendering to PNG files (24bit with alpha. Does 32 bit add much?) Is this the best format if the results will be going into After Effects?

On a related note, if I have an object in the scene with a matte material on it, the matte material is showing up in the alpha channel. How do I prevent this?
If I check the option in Octane to "Use object render settings" and turn off the Receive Shadows and Cast Shadows in object properties for the object that is using the matte material, I don't see any difference.

Thank you.

Any takers?

Has anyone had experience dealing with the antialiasing, where they are rendering with the alpha channel on (against a black background), but with an HDRI environment, and then need to composite the results onto a background that doesn't approximate the brightness or color of the HDRI environment?

Make sure "premult_alpha" is ticked on your camera.

best,
O

Thank you! It looks like that may have done the trick.