Substance textures compression in the UI?

Hey guys! New to both UE4 and (somewhat) to Substance Designer. Having a lot of fun so far, and finding it a lot more interesting to work with than Unity x). I really like that we have substance support in UE4, but I have a question in regards to memory usage and format as they are displayed in the UI inside the engine.

After importing a substance and generating its textures, they all appear to take up a LOT of memory and their compression shows as R8G8B8A8 and the compression settings are grayed out. In one case the BC image is 21854kb while the same image exported from SD and imported to have DXT1 compression is only 2731kb. I can see in the grayed out Compression settings box in the SD texture that it’s set to Default (DXT1/5, etc) so is this 10-fold (almost) size increase just a bug in the UI, or is it really in some other format? :P.

I also wanted to ask this on the Allegorithmic forums, but trying to log in there just gives me a database error so here I am x).

Try making at least one edge of your texture a power of 2 in size. I had to do that before my UI textures would get compressed with DXT 1 or DXT5.

I had to resize the source texture too BTW. If you just pad it in the editor, it still seems to want to do R8G8B8A8

I wouldn’t recommend using the Substance plugin for importing textures. It can be a little heavy and it has some weird choices for how it compresses textures. My recommendation is just exporting 8 bit bmp files from Substance and importing them normally.