The shady part of the terrain is slightly flickering when I move or rotate the camera. Video compression makes it a bit harder to see.
It's a very simple material generated in-code. I create a HlmsPbsDatablock with default-init'd macro, blend and param vec. Then a samplerblock where I disable filtering and set the texture (also generated; it's just a 64x64 pixel texture).
Now that I write this I actually don't know where I set it to have a specular value at all. It's also not a terrain geometry. I'm using manual meshes. No roughness, fresnel or tesselation. Scaling is (1, 0.5, 1). Maybe that's causing the issue?