Render Alpha Only

[user_deleted]

Hello
I did a keylight keying, and want to render the alpha channel only...
only the black/white frames.
how can i do this? i can't find any useful help in the manual.

thank you very much

[user_deleted]

QUOTE(traumpirat @ 07/17/08, 10:58 AM) [snapback]288442[/snapback]
I did a keylight keying, and want to render the alpha channel only...
only the black/white frames.
how can i do this? i can't find any useful help in the manual.

well, i see three options:

• reorder to "nnna" and save to .iff or .tif which gives you a 1 channel image with only the alpha. if that doesnt work because you need it in an app which doesnt understand that, then..

• reorder the alpha to "aaan" which gives you a b/w 1 channel image containing only the alpha, or..

• use a file format which compresses large areas really well, like .iff, .tif with lzw, .mov with animation codec etc, then copy the alpha in a black 1 channel image.. file sizes should be nearly the same as option one and two.

hope that gives some ideas
++ chris

[user_deleted]

yeah! that's what i was looking for, thank you very much.
reordering worked very well.

best whishes
andreas

[user_deleted]

QUOTE(zem @ 07/17/08, 09:22 AM) [snapback]288477[/snapback]
- use a file format which compresses large areas really well, like .iff, .tif with lzw, .mov with animation codec etc, then copy the alpha in a black 1 channel image..
hope that gives some ideas
++ chris

i new about iff, but tif with lzw and mov with animation is quite new to me and thanks a lot for the information.

[aaron-marine]

well you really dont even have to do that really, because off the top of my head doesnt keylight have the option for viewing just the alpha mask? i remember accidently leaving that turned on and when i rendered that was all i got.