Which image format is the best for unreal engine PBR shader
Files get automatically converted in the edtior, so the question is what format do you prefer to work with. PNG is fine if you want to save on disk space and get previews, but I would not use it if you are using the alpha channel, because Photoshop does dumb things with it, and 16bit PNG files are sometimes as issue as well. TGA is my normal go to, there’s never any weird workflow issues, but you do not get an image preview of the file in Windows, but there is software that will add that support. There’s also people that love .psd files, but I’ve been mostly moving away from Photoshop for textures.
The correct answer is .DDS, but that’s because that is what all textures are converted to when they are imported.
For authoring, an answer is whatever file format doesn’t incur any compression loss or compression artefacting (is: don’t use .JPG), or whatever you like using.
I personally use .PNG for most things (because its easy and it works), and .TGA when I need to use an alpha channel.
Which… is basically the same thing ZacD said, so yeah.