Grey Border Around Transparent GUI

posted by Springheel

This problem keeps cropping up, so I'm storing solutions here as I find them.

For some reason, a .tga image with a transparent background will sometimes apply a thin grey border around the object in the center. This doesn't happen all the time, but it's annoying when it does. I haven't been able to track down the cause.

I've had no trouble adding graphics with transparencies before while working on the failure and success screens, so I can't figure out what's going on. Even a simple black box gives me a grey border.

Oddly, when I change the colour of the box above from black to blue, the grey border didn't appear.

In the image below, the bar above the lightgem is what the photoshop image looks like (and what it should look like in game), and the bar below is what it actually looks like in game. It's small, so you have to look closely, but there's clearly a grey line around the bars and it looks like crap.

It might have something to do with soft edges around the object, although sometimes it seems to happen with solid edges as well. I'm working on this issue right now so I'll post some more shortly.