I'm working on some texture files for the game Fallout 3, and was pointed to PDN, since it has support for the DDS files used by the game. I've been able to use the eraser tool to some extent to create transparent portions of a layer when combining multiple layers, but it seems to be missing some functionality, plus I need to be able to edit the alpha layer separately from the other channels.
I can't remember what image editing software I used before, but it belonged to my workplace, so I couldn't keep it. Anyhow, when you used the eraser tool, left-clicking raised the transparency by whatever settings the tool was set, and right-clicking lowered the transparency. This way you could easily get the transparency just right. However, I don't see any such option with PDN. In fact, I'm not even sure how to just make the image completely opaque so I can start from scratch.
Next, it would be tremendously easier if I could separate the different color channels (specifically alpha) into either different greyscale images or different layers, work on them individually, then recombine them into a single image. I found the Alpha Map plugin that lets me convert the alpha channel to greyscale, but when converting the greyscale back to alpha I'm left with no RGB information. Copying the original RGB information seems to also copy the original alpha information, over-writing any changes I made using the alpha plugin. Any ideas on how to edit the alpha layer without saving as a file-type that doesn't have transparency to make it opaque then manually using the eraser and hoping I don't make a mistake?
The game uses the alpha layer as its own greyscale image (i.e., it's using RGB to make a 24-bit image and alpha to make a separate 8-bit image), so it's easier to work with if I can see just the alpha layer, instead of trying to guesstimate what it looks like based on how transparent the image is. I'm sure there's probably something stupidly obvious, but I'm not seeing it. Any help would be appreciated. Thanks!