So I’ve made an RVT for a landscape. I’d like to use the normal blue channel to pack in some extra data for my grass blend to use then derive the normal z after the fact. The question I have is what exactly does the RVT do to the normal z hidden transform wise when it brings it along?
The documentation says it does nothing (Runtime Virtual Texturing in Unreal Engine | Unreal Engine 5.3 Documentation), but I know this isn’t true because anything I drop into there disappears unless I remap it into -1 to 1 range. Trouble is, when I do that it blows the contrast through the roof. The closest thing to looking right I’ve come up with is below, but I’d like to get a 1 = 1 situation. If I knew what was being done to it I could undo it.
Here’s a splat texture dropped into basecolor:
Here’s what comes out when you put it through the z channel of the RVT normal:
Here’s what it does when you map it to -1 to 1 then go through the RVT normal then remap it back:
Here’s the result of the above code snippet (notice my lack of weird artifacts down in H8, but the huge contrast difference from the original: