Issues with terrain LOD distribution

Versions 1.7 and 1.7.1 (not tested 1.6), PC Nvidia

I’m experiencing rendering issues on terrain. I’m using a very basic material model (Domain Terrain, Lit, Opaque) with just 4 texture maps (color, metal, rough, normal). Most of the time it is OK but I can catch it at the right angle / camera position and it looks like this:

This can be apparent in both editor and game view. It pops in and out depending on small camera angle / position changes and tends to be in the mid range of the view. Setting terrain LOD Distribution to 0 removes it, but even a tiny value, e.g. 0.001 in LOD Distribution and the problem is back.

This is with a very lightly loaded machine / good frame rate.

Any thoughts?

I found that I could also fix this by changing LOD Bias to -1 (effectively dropping 1 level of LOD optimisation). It seems to me that the default values aren’t quite right somewhere.

This topic interests me, but not knowing the actual material textures, I’d be curious about maybe a green and a red circle indicating what’s correct in the above, and the part that’s borked =)

Or in a few words, would also do I guess :grin: not that I can help, I’m just getting started in Flax and I’ll be jumping on terrains as the first topic to explore indeed.

Hi thanks for checking in. The material is a very basic sand PBR, but I can generate the same effect with even the default terrain material. The problem is that the terrain is smooth and continuous, the little steps visible in the image are a LOD render issue. I suspect that the LOD calc is snapping data points to a coarser grid, but I have not looked into the code as my knowledge about that is minimal.

1 Like