[SOLVED] billboarded trees sometimes flying over terrain

[demostenes]

Few percent of billboarded trees is flying over the terrain. Changing LOD settings for terrain makes no difference (I was double checking this to be sure it is not caused by little bit different shape of terrain for distant LODs).

 

http://img89.imagesh...40/21966645.jpg

[frustum]

Please use terrain relax tool to compensate high terrain flatness values.

[demostenes]

If you mean parametr flatness, I ve tried in small steps up to value 300 (total destruction of terrein details). In smaller values it has no effect, in bigger values it is even worse (I ve regenerated grass after each step):

 

http://img402.images.../9764/flatd.jpg

 

I have no problems with standard grass.

[ulf.schroeter]

Have you tried this Terrain Relax Tool ?

[demostenes]

Have you tried this Terrain Relax Tool ?

 

Well, it works only with very high values like 1000, which makes my terrain almost flat...Btw, I am not sure I am using this tool properly, only think it does is flattening the terrain, no optimization of density like on this picture:

 

https://developer.unigine.com/en/docs/1.0/tutorials/terrain/3_flattened_sm.jpg

 

Same for the in engine flatness option.

[manguste]

Yes, TerrainRelax tool simply bakes Flatness for the terrain.

 

So if terrain's Flatness is set to 0, and billboards are still flying, Offset parameter of the grass can be the culprit. Maybe its spread value is too high, for example. Please check what do you have for it. (If not, please attach a screenshot of grass and terrain node options).

[demostenes]

Yes, TerrainRelax tool simply bakes Flatness for the terrain.

 

So if terrain's Flatness is set to 0, and billboards are still flying, Offset parameter of the grass can be the culprit. Maybe its spread value is too high, for example. Please check what do you have for it. (If not, please attach a screenshot of grass and terrain node options).

 

Spread is zero i this case. I ve put some negative offset there. It is not perfect, but for now it is sufficient.

[manguste]

Yes, that's exacrtly what negaive Offset is for!

 

Without a negative Offset there could be a really small gap, as a billboard itself and the texture on it differ in size a bit. But it's really small, hardly noticeable and nowhere near your result:

 

All in all, solved.