Alpha Channel Image Problem 2005-02-22 - By peterb
Back
there' s a zillion ways,
some of them being:
on the fileinput, select "alpha from luminance" rather than "rgba" or you
can do this with swap component too (check the r g or b box in the right
most row) This will put the luminance (intensity) in your alpha channel.
cutout (put your rgb colour image in the green slot, put you alpha/mask
image in the blue slot)
now the image will "clip" as you said. Keep in mind that you might have to
use the premultiply option, or select "not premultiplied" in you
over-operator downstream.
you have plenty of extract nodes, like luma extract, chroma, color
extract,... that create alpha out of the rgb image.
Thats should get you started.
> Hello everyone, I know that with the TIFF file format it can save alpha
> channel although it does not seems to always work for some reason and
TARGA
> if saving in photoshop (other then CS) will not save alpha channel embeded
> into the image ! So my question is if you have a seperate image file that
> is just the alpha channel how do you plug it into the render tree ? I've
> tried layers and mix color shader with no results as expected, so how is
> this done so that the alpha channel "clips" out the portion that is not
> suppose to be there and your image appears as it should?
>
> Thank You
> ---
> Unsubscribe? Mail Majordomo@(protected) with the following text in body:
> unsubscribe xsi
>
---
Unsubscribe? Mail Majordomo@(protected) with the following text in body:
unsubscribe xsi
|
|
