I'm trying to render some windows, reflecting an environment map, and to be transparent to let light enter inside the house. There are two windows facing each, and I need to see through both, and keep the alpha channel here.
Here are the window's material nodes that do (half) the trick :
But, as you can see, there is no reflection on windows, which is needed. The is Camera Ray is overriding the reflections too. But if I don't add the is Camera Ray to the is Shadow Ray, the background is rendered instead of alpha channel:
Is there a way to have a "glass" material with reflections of an env map, light passing through and alpha channel through?