Landscape Reflections - Being PBR is Not Enough.

[Deathrey (DeathreyCG)]

@Frenetic_Pony

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.

It is called Composite Texture in Unreal, and I have absolutely no idea why so many authors are not making best use of it.

But it addresses only texture level details, not geometry details, which play pretty important role with landscapes, and will still result in glare on landscape, unless something is accounted for during shadow projection.

There is one remedy, I might suggest for specific case from rendering side. That being, store sun microshadowing in additional gbuffer target, so that it can calculated in material, and when averaging out, will get you distant directional occlusion. Microshadows would be applied during shadow projection pass.