Is this really the best UE4 can do in regards to texture quality? (the evils of dxt)

I’m trying out a skybox in the engine and well… the results are pretty horrifying when the texture has been compressed.

Here’s a screenshot of the skybox with “defer compression” ticked (please don’t mind the sloppy stitching, this is a quick and dirty version I made just to test out image quality and colours etc. in-engine). Granted it’s not perfect as is. There is some colour banding in the darker areas but I doubt I can get it much better since 24 bit colour in general seems to have a hard time with dark colours. However, I can live with a skybox of this quality.

Once it’s compressed however, it turns into this horror. I feel this is a completely unacceptable image quality for this day and age. As you can see the darker parts of the image collapse completely into something that looks like it’s out of 1992.

Is there any way I can make this better. Either by changing compression settings or working with the source material? I’ll even take new pictures if I have to. I don’t want to make it brighter though because it’s supposed to be an evening sky.

Now I’m sure some people will say use HDR, well, I did take 3 exposures per pic (0,+1,-1) so that I could turn them into HDR. But no matter what program or what settings I used to make the HDR image I would always find that there was more or less *no *new colour information in the result. I could always reproduce an exact copy (more or less) of the tonemapped file by simply matching contrast and brightness etc. on the normally exposed original picture to match the tonemapped picture. So I ended up using just the normally exposed images without HDR since it made no difference. I feel like HDR is overhyped and only really useful in images with very high contrasts, but maybe I’m just doing it wrong?

Another problem I have is that the texture is *way *brighter in the engine than in the source picture. I have the skybox set to unlit of course. So my second question is; why does it do this and how can I fix it? Here is a picture with the source image overlayed on the in-engine result.

Any tips and information is extremely welcome! Surely there must be some way to have dark textures in UE4 without them being compressed into oblivion?

You can set it to a different type of texture so that it uses less compression. The default will have the most, but there’s things like the UI textures that have less.

You can try using a Grayscale compression. It costs just as much as the standard, but it just uses one channel uncompressed. Otherwise, I think the problem is you want very soft gradients, and with only 256 shades of value, you just can’t get really soft gradients. I’d suggest adding a noise filter over your texture to dither the banding if it gives you too much trouble. Or you can always brighten up the texture to give it more contrast.