Is this possible ? (transparent channel)

Hi guys,
I’m making GUI interfaces for audio applications, and do most of my work in Photoshop, but I would like to find out if it’s possible in Blender to create knobs and then export them to a targa file withtout the background in it ? So what I need is just the knob with it’s shadow on a transparent background so I can place it on other backgrounds in photoshop, so far I don’t seem to find how this works.
thanks for the help,
Hans

Render Buttons->Premul

Also RGBA instead of just RGB

Thanks guys, but when I do this and import the TGA file in photoshop, it still has a black background, is it possible to have a transparent background with the rendered object only ?
thanks,
Hans

You have it already. Since PS CS (as far as I know) the alpha channel of .tga’s not automatically masked out. You can simply go to the channels tab and use the alpha channel there to get a selection of your rendered objects and delete the BG / use a layer mask with the selection.
If you don’t find the channel there you might have done something wrong though.

Ok, I just checked with PNG files, and this seems to work perfectly, when I export the file I get a transparent background and just the object in it, but when I do this with TGA, I automaticly have a black background whe I open it in Photoshop, why ?

thanks,
Hans

Hi Mike, thanks, I can see the channel, though I don’t seem to be able to correctly remove the black background in the targa file or mask it, how do you do that in Photoshop btw ? I just checked with for example TIFF format, where there is a perfect tranparent channel, so I might go with TIFF files instead of targa then … is targa better quality ?

thanks,

Hans

yes, targa is uncompressed/lossles. did y have rgba button on in render panel, if y didn´t click on it…
bye

edit-> y can get the shadow done with plane behind button and for the plane set in shader shadow only, should work i am not 100% sure of this though

Thanks, yes, I had that activated, and in Photoshop, I see the alpha channel, but what I don’t seem to understand, it’s black while in TIFF and PNG it’s transparent. Though I installed the new TGA plugin that should handle these as transparent background in Photoshop, but it doesn’t seem to work for me here and I don’t understand how to mask it by hand …
thanks,

hans

Ok, I think I have it working now, I can cut out the black background in the TGA file, looks perfect now, thanks so much guys. I’m going to check out the shadow tip, though I can easily create shadows in Photoshop.

thanks,

hans