Unable to use the background render element or alpha

[manishpaul_simon]

Hi,

I wanted to render the scene attached to this post with the background masked out.
I made sure to switch on invisible in the dome light and I had no background for this scene. (my sunlight and environment were turned off)

But it simply rendered the background as black.

And the alpha was simply showing white. I also made sure to save it as a png.

What's the best way to mask out the background and later use it in photoshop if we're using a domelight to light our scene?
I couldn't find an option to add a material ID to the dome light background.
And the alpha and background were simply rendering out as pure black and black.

[83cino]

Hi,
you have to go to your window glass material options and than into refraction -> affect channels -> color+alpha.

[manishpaul_simon]

Thanks a lot