how to create proper decal textures? (Photoshop)

I seem to get constant artifacts and faulty blending when I create my decals in Photoshop and then apply them over surfaces in Unreal Engine. I think it has something to do with properly handling alpha channels.I have found plenty of tutorials on how to create a decal material in Unreal Engine however I have not found any tutorials which explain how to properly create the decal texture itself in Photoshop.

I am looking to not only get some cracks and dents for surfaces but also perhaps color decals so that I wouldn’t have to create many different wall textures for walls. as well as color textures such as graffiti.

sometimes after importing my decal and placing it on the wal Il only see blocks of black or white color its like the editor turn down the tolerance for alpha and turned it into blocks. The blocks from thr decal however cover the area where the mask was created

Hey, are you having trouble with artifacting peaking through areas that are supposed to be transparent, or does the image quality itself look poor?

For the transparency artifacting issue, you’d be surprised how much info exists in the darker tones. This is unwanted information. If you have a color manager for your gpu I’d recommend temporarily bumping up the gamma on your monitor all the way and then look at your alpha channel in photoshop. I use this trick to make sure my blacks are as clean as possible.

If you’re having trouble with poor image quality, I noticed UE4 doesn’t like transitioning between shades of grey (in the Alpha) and that can cause artifacting. Try making sure your alpha is as solid as possible.

Are you setting the proper material domain in material properties? It should be Deferred Decal.

Yep. I think it might be the file format or the etyp of alpha setting that I pick during export

You can check the texture’s alpha channel in the content browser by opening the texture. If you can’t see it there then there must have been a problem while saving the alpha. I suggest 32bit TGA for textures with alpha channel and make sure the alpha mask is visible while you save it in Photoshop.

Hmm that sounds like a strange issue. Yes I also recommend 32bit TGA files.
You may try experimenting with material parameters such as roughness and metallic as well. Some settings can look strange.