Turn a black and white image into an alpha channel

lkraan

I am a noob with Photoshop and have really used it for the first time for a character skin. I was always a PSP user but decided to take the plunge

I have made a separate black/white image as an opacity map for 3ds max. Now that I want to get the model into UT2k4 I want to turn this black & white image into the alpha channel for the head texture and I can't figure out how to convert this separate opacity image into the alpha channel for a different image file. They are both TGA's with the same resolution.

Can anybody explain how this can be done?

Rick Stirling

Go to the channels palete.

Create a new channel - this is an alpha by default.

Paste the black and white image into this channel

Save the image as a 32 bit TGA

KDR_11k

For an unpatched PS7.0 with the borked TGA exporter or if you love transparency for some reason:

-Do same as above minus saving
-CTRL-click the channel icon to turn it into a selection
-Convert the background to a layer
-CTRL-SHIFT-I
-DEL
-Save

lkraan

Got that to work. Thanks guys!

Hollowmind

Or for PS7 you could just download the old tga plug-in from the Adobe website so that it works the same as earlier versions.

http://www.adobe.com/support/downloads/product.jsp?product=39&platform=Windows

Scroll down to the first PS7 patches and you'll find the targa plug-in there. You didn't say you were using PS7 but I thought it'd be good to note here since someone did mention PS7's screwed default tga plug-in, hehe.

KDR_11k

That will of course make it impossible to export the image transparency as alpha and prevent you from exporting alpha when you use the channels to save your selections. If you rename the patch before copying it over you can select both though they'll have the same name in the selection menu.

JO420

i personally like the png format, no alphas needed for transparencies make for cleaner looking texture which use em

KDR_11k

The old TGA exporter from 7.0 will also use the transparency for alpha, I've used PNG a lot but it saves damn slow and that got on my nerves.

Ruz

acxtually I learned at work that the photshop 7.0 alpha is not buggered, its just that it is not viewable by default. forgotten the exact process, but I prefer the pshop 6 method.

Asherr

i just went to that adobe link and tried to download the targa plugin. it gives me a 'could not be found' and 'this website may have been moved or had it's name changed.' when i try to download it.

KDR_11k

Strange, worked for me two days ago.

Sett

I use the .dds format for export to Ued.

The only prob. I had was that I had to flatten the image before export.