Render to file with transparent background?

Hi all,

I’m interested in using the rendered out put of Blender as input into a different program. However, it would save me a lot of time if I could get Blender to output a graphics file that had a transparent background. Otherwise, I have to do some tedious work with Gimp.

Can this be done?

TIA,
Mike.

http://wiki.blender.org/index.php/Manual/Output_Formats

I was close. Needed to use color number 0 and output png. This paragraph from the link provided got me going.

If the option “RGBA” is specified, standard colour number ‘0’ is used as the transparent colour. The format MUST support an alpha channel as part of its specifcation; for example, if you choose a Jpeg format (whose specifcation does not support alpha transparency), clicking RGBA will not magically add an alpha channel; it will be saved as RGB only.

thanx again.