RGB texture mask compression artifacts

I’ve been using RGB channel packing for roughness, metal and AO textures with no compression issues. However, I’m trying to created some pattern masks in RGB (for a fabric texture), and the hard edged masks look horrible in-game due to the compression.

I’ve been reading online about UE’s compression issues and have found a lot of info, but no real conclusions. I’ve tried both PNG and TGA, every compression setting available in UE, as well as playing with compression quality (which didn’t seem to change anything?). All my experiments lead to the same artifacts.

Is there an actual solution to this or should I just load in my masks as separate texture files (which will greatly decrease the amount of variety I can include for my instances)?

RMA packed textures generally compress decently because the 3 channels contain similar information. The channel cross-talk compression artifacts get more apparent when the 3 textures are more high-contrast and contain drastically different textures. Have you tried BC7 compression? I forgot the specifics and if it compresses all 3 channels together, but each channel gets more bits which may alleviate some of the crosstalk at a memory cost.

Thanks for the info! I’ve tried BC7, but still too much crosstalk. Looks like a case of simply needing to import separate textures.