Alpha rendering

[fmasso]

Hi, I have a question.
I often have to render a model both with and without a background (to better explain myself with or without the check on the alpha checkbox next to the image format).

What I do now is two separate renderings, one with alpha enabled and one without alpha enabled. But this doubles the time and for long renderings sometimes can be a problem.

My question is: is there a way to render with and without alpha at the same time? I tried to play with the rendering levels, to export everything to a PSD and then edit it with photoshop, but I still haven't succeeded, can someone help me?

Thanks in advance.

[INNEO_MWo]

I would prefer to render with alpha and add the background in post. And if the background should show the environment, I would render only the environment (same camera) without the model (with 1 sample it is very fast) - and this technique can be automated using studios (adding both studios to the queue)

[HaroldL]

Have you tried rendering in the background? I've done that at work when I needed to render an image  while setting up another. Be sure to adjust your core usage accordingly so you have enough cores for each render. And it may increase your render time a bit.

[andy.engelkemier]

Some of these are good solutions, but from the sounds of it you may want to look into render layers.