I would like to render an image with a transparent background so I can easily set a background image behind it in post-production. In my case, I am looking through two curtain walls until I see the background. Since the glass is an object I cant just use the alpha channel to cut it out afterwards. It seems to have something to do with the environment texture, but if I turn it off I don’t get such good results regarding the light in the image (basically almost everything gets dark). I read something about using channels but I can’t seem to figure it out. See the image attached:
Glass will always be opaque over background. You can use Cryptomatte / Multimatte or Material Random Color elements to select glazing and then Reflections / Specular / Refraction elements to somehow edit the glazing in post production.
I’m not sure there’s an easy solution.
Oh wait, there is.
You can use your background image directly in V-Ray: