editing a textures alpha in gimp for tf2?

Don

I'm trying to make a texture for a model in tf2 with gimp, and I want some of it to be transparent. This is done by editing a text file that tells the model to use the textures alpha channel. things in the alpha channel that are white are transparent and things that are black aren't.

But I don't really know how to edit the textures alpha.

Here is a video I've seen that explains how to make one in photoshop: http://youtu.be/-X5QGx2TP_8?t=33m57s

Does anyone know how to do exactly what he does in gimp? whenever i duplicate one of the rgb layers, it isnt black and white like it is in ps. i'm also not sure how to have it turn into the alpha.

Can anyone help?

Eric Chadwick

I'm not a Gimp user, but after a bit of googling it looks like you need the decompose script.
http://www.gimptalk.com/index.php?/topic/12140-alpha-channel-how-to-edit/