Texture Alpha as Map-To Alpha

Support Basics & Interface
1

Hey all!

I’m familiar with how to use an image’s alpha channel to make the background color show through.

What I’m trying to do is use the Alpha channel of an RGBA image to affect the Alpha value of the texture (ZAlpha or RayAlpha, doesn’t matter).

Right now it seems the only way to do this is to save the Alpha channel of the image as its own 8-bit grayscale file and apply THAT as a second Texture channel. Is there a faster way?

If there isn’t, I’ll request a feature for the Image pane of the Texture panel called “OnlyAlpha” to accomplish this with two texture channels using the same image.

2

Gifs, pngs(I think), and tga files are able to handle transparency, or alpha. JPEGs can’t. When you select an image to use, in texture buttons(F6), there is a button above the “Load Image” button, called “UseAlpha”. Dunno if that is what your looking for.

3

save the Alpha channel of the image as its own 8-bit grayscale file and apply THAT as a second Texture channel. Is there a faster way?

UseAlpha in the Image tab should do it failing which what you say above is the next best.

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4

Oh, the Alpha channel is definitely there: it’s a TIFF with the Alpha in place and that’s all working just fine. What I’m trying to do is to have Blender use JUST the alpha channel for a Texture… ignore RGB and just use A.

“UseAlpha” doesn’t do the trick: even with “NoRGB” turned on you still get the color information in your Alpha channel (modifying OBJECT alpha… NOT image alpha).

Seems like a feature request to me!

Thanks all,