Landscape Reflections - Being PBR is Not Enough.

[Frenetic_Pony]

@rosegoldslugs

It’s a similar issue as to what happens with foliage. Microfacet shading becomes not so micro at a distance. I’ve been able to alleviate it somewhat by using mip sharpening for textures like normals and roughness so their per-pixel detail is maintained for a farther distance from the camera. You could also try the normal composite option for the roughness texture, which is pretty similar to what Sledgehammer did for WWII, although their’s was specifically meant for solving this problem and not to reduce specular aliasing.

This one’s rough, more resolution, making sure temporal AA is on, but most importantly turn on… ***** I can’t find it and can’t remember what it’s called. It’s a texture filtering technique everyone else in the world calls Toksvig after it’s originator, but UE4 supports it yet has some specific term for it that no one else uses just to confuse people.

Anyway, if anyone can remember what it’s called in UE4 that’d be great. But it changes the roughness mip maps to take into account how rough the normal maps are, so this exact scenario happens less, alongside other unwanted things like fireflies. It’s really, super cheap too, even if it’s not 100% effective it’d definitely help anyone looking at a solution for this problem.

By the way @Dethrey OP is 100% correct here, in a perfect render this doesn’t happen. It’s just an effect of mip maps “flattening” things out and making them look smoother than they should the farther away they are.