Tell me a bit about how decals work please

[2007CA]

Doing a school project in unreal, needing to add a few decals. They have transparency via an alpha channel. Seems though that the only way to get the correct color is to put my RGB output in the emissive, which could give me problems if the decal is in a dark area, or use the masked blending mode, otherwise the color will be totally off even if the transparency is fine. Masked blending mode just looks totally nasty and soft masked doesn't work even a little. Right now I can work around all this, but for future reference, how are good decal materials set up?

[Gradius]

In what way arn't the colours working? Can you give us a screenshot of what your decals look like if you make them normally (with just a normal decal vmt).

[2007CA]

In what way arn't the colours working? Can you give us a screenshot of what your decals look like if you make them normally (with just a normal decal vmt).

Oh no I was asking about the Unreal engine, so no vmts. But nevertheless, here is what I was dealing with at first.

[Gradius]

Ah yeah, I forgot the site now has an Unreal section.