Noisy mountain snow

[ISC_]

Hi everyone!

 

I have a long standing issue with snowy mountain lods (using MM with lodpack and BDS 3+). The snow gets extremely noisy/grainy on medium-distance LODs after running DynDOLOD. The picture shows a noisy LOD while the near cliffs and far mountain are both smooth (noise is much worse when moving, like a stack of ants). What could be causing this and how could it be fixed? I have fiddled around with SSEEDIT and various textures, but honestly I don't have much of an understanding of how LODs work.

Since the mountains are ok before generating new LODs, could DynDOLOD be set up to not generate LODs for mountains, if I find no other solution? 

 

Thanks for any input on this.

[z929669]

When running DynDOLOD 3 alpha, create a new mesh rule:

mountains | Level0 | Level0 | Level1/2                          (VWD | FarLOD)

Then set distance LOD under DynDOLOD settings in game to something like (LOD4 | LOD8 | LOD16) 50,000 | 100,000 | 200,000 ... you can play around with this setting.

This all could cost you some VRAM but FPS should not be affected much if at all.

PS: these settings should also work for DynDOLOD 2.xx, but level names are different.

[sheson]

As you wrote MM has a LOD pack, which replaces the vanilla LOD models and some object LOD textures for mountains, including pre-rendered ones that can not be currently generated automatically. Make sure they are installed correctly when generating LOD. They typically used to be fine.
If you do not have this problem with the vanilla LOD models/textures, then check with the author of MM about it. The LOD model and texture have an effect on the snow LOD shaders.

The snow LOD shaders which are applied to object LOD are the material object shaders with the form id  006AE38 ("SnowLODMaterialHD") for the nearest LOD mountains that use the full mountain texture and the form id 00050372 ("SnowLODMaterial") for the further LOD mountains that use the pre-rendered object LOD textures. The shaders are applied "live" in the game.

Whatever plugin is the last to overwrite these shader records wins and is responsible for the final result of how this snow cover looks.

Not generating LOD for something means, something won't have any LOD. As you can see from above, the used LOD generator does not matter, it is all in the LOD assets and other plugins modifying LOD related records.

[z929669]

We do also use the MM LOD pack in our guide, but my experience with the MM LOD is that distant mountains are white and a bit grainy. When they load full, they look totally different (like they should). The mesh rule I mentioned (from OP BTW) resolves this completely, so I think the MM LOD files may be the grainy ones. I assume setting to Level0/1/2 overrides these in some way (maybe the LOD shaders don't get used):

[sheson]

The snow/ash LOD shader identifiers are always applied to all LOD levels for a reference.

If you want LOD shaders and full model shaders to match exactly, the LOD and full model shaders need to have the exact same settings, and the model and textures need to be the same as well. Typically the LOD level 0 mountains use the full texture. Having only two snow LOD shaders and two ash LOD shaders available limits what is actually feasible.

[ISC_]

Thank you for the quick and serious replies, super helpful!

I managed to resolve after weeks of trying, thanks to your comments. I started looking at what affects the HQ LODs specifically and noticed that MM (regular mod, not the LOD pack) comes with a HQ LOD normal map which is very grainy. So for anyone else with the same problem - find mountainslabHQlod_n.dds and blur it. I used gaussian blur in paint.net (set at 2 or 3) and voila, smooth snow on HQ LODs

Edited April 13, 2021 by ISC_