jscottsmith wrote:1) Ok. Thanks.
2) Hmm. Not working for me. Could it have something to do with the glass material? Or the SU sky background?
A HDRI for the octane environment shouldn't matter, it should still save out alpha where you are seeing the environment.
But glass will matter, according to octane, glass is a material and blocks line-of-sight to the environment. If you want alpha where your glass is your will either need to remove the glass or set it's opacity to something less than 1 so that some rays go straight through, hit the environment and 'pick up' the alpha.
Hope that makes sense?