Issues with terrain LOD distribution

Graphics
#1

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:

image
image1788×711 34.1 KB

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?

Flax Engine Update 1.9
#2

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.

#3

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.

#4

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.

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