[Krelus]

I was reading the tutorial on texturing whilst browsing the wiki, and I'm trying to wrap my head around how Shinemaps work (or at least, how to manipulate them using GIMP.) Here's what I got out of it, so correct me if I'm wrong: The RGB values determine the luminosity, while the Alpha channel controls the background reflectivity. I understand how the Luminosity works - I've adjusted that to great effect. The problem is, I don't want mirrorlike ship hulls (I'd rather completely nullify the reflections altogether) and can't figure out how to independently manipulate the Alpha channel in GIMP. Can anyone point me in the right direction?

[Retsof]

Do you mean the alpha of the whole image or bits of it?  for the whone image you just move the opacity slider in the layers dioluge.  For specific sections you can use the eraser, and you can set the opacity on that too if you don't want too much.  also you could put where you want transparent a certian color, then do a color to alpha.

[Krelus]

Do you mean the alpha of the whole image or bits of it?  for the whone image you just move the opacity slider in the layers dioluge.  For specific sections you can use the eraser, and you can set the opacity on that too if you don't want too much.  also you could put where you want transparent a certian color, then do a color to alpha.

Tried that, all it did was dim the shinemap's luminosity and it had more or less no effect on the background reflectivity.

[Flaming_Sword]

I normally use a layer mask to play around with alpha (assuming the original texture did not have an alpha channel).

Added a layer mask, played around with it until I was happy with the results, then applied the mask and saved as DDS or whatever.