I’m experimenting with texture bit packing - I used substance designer to pack roughness and ID mask into the alpha channel of my color texture (8 bits split into 5 bits for roughness, 3 bits for mask). Here are the original textures:
And this is the packed one:
I can unpack this in substance designer and it works fine, though they lose some depth which is of course expected:
The issue is, when I try to do the same unpacking math in UE material editor, the first element unpacks fine (roughness), but the second one produces this strange visual bug/noise:
this is the unpacked roughness:
and this is the unpacking logic in material editor:
Any help/insight for why this is happening would be appreciated. I am also attaching the packed texture if anybody would like to test it: