Mountain Fog Clouds - Popping in and out

[Hypobolic]

Hi there SSE braintrust.

So, I've gone through the entire STEP setup and modding for SSE, and during the Benchmarking section I came across a rather noticeable popping of some sections of mountain fog. So far the position

cow tamriel 40 -24

to benchmark the framerate consistently demonstrates this problem for me.

 

I am using Obsidian Fog, which is in the STEP list of recommended mods, but it is through the entire Obsidian Weathers mod, if that makes a difference.

Here are three screenshots. The first shows the fog fully intact, the second shows a highlight of the area that pops in and out, and the third shows the fog missing.

Fog intact

Fog highlighted

Fog Missing

I can very easy reproduce this by just moving my view by a single degree left to right. It feels like there is a vertical line, that goes all the way up the screen, that if I move the cross hair over it from left to right the pieces fog pops in and out.

I've googled this extensively and I am definitely not alone with this problem, but I have yet to see anyone with a solution. There is a separate issue with mountain z-fighting that many people experience (and shows up in my searches), but this is definitely not that problem. The proposed z-fighting solution of setting fNearDistance = 13.000 does nothing for this fog popping problem.

Anyhow, I'm hoping that someone here might have any additional insight or possible solutions the problem. I welcome it.

Thanks!

~EDIT~

Just wanted to note that I have gone through all of the LOD steps, so this is a post LOD problem. Not sure if that helps.

Edited August 18, 2022 by Hypobolic

[DoubleYou]

I believe these are neverfades. Neverfade distance renders to fSkyCellRefFadeDistance * fLODFadeOutMultSkyCell units. Increasing fSkyCellRefFadeDistance may fix the issue. Below are my current settings.

[LOD]
fLODFadeOutMultSkyCell=1

[MAIN]
fSkyCellRefFadeDistance=327680

 

[Hypobolic]

Thanks for the quick reply!

So, I just check my .ini files and those setting look the same. I actually had fSkyCellRefFadeDistance jacked up to 600000. I think I tried an earlier fix and just gave it a massive number. The problem still persists.

Thanks

[DoubleYou]

Try using this mod instead of Obsidian Mountain Fogs. 

 

[Hypobolic]

Okay, checking it out. I am using Obsidian Weathers, but it looks like if I can just remove the ESM flag from this mod and load it after OW. Gonna have to run LODs again to get a proper gauge on if it's a good fix or not. Will update after testing.

[z929669]

1 hour ago, Hypobolic said:

Okay, checking it out. I am using Obsidian Weathers, but it looks like if I can just remove the ESM flag from this mod and load it after OW. Gonna have to run LODs again to get a proper gauge on if it's a good fix or not. Will update after testing.

It looks like you will need to remove or reconcile the conflicting FormIDs in one or the other. Just changing the flag would not affect the doubling up if I am interpreting correctly on Nexus.

[Hypobolic]

Actually, would you happen to know if those fog/weather type clouds are considered billboards or not? Just trying to see if I can get away with only running TexGen and not going through DynDOLOD, which is a pain cause I'm using Open Cities.

[Hypobolic]

3 hours ago, z929669 said:

It looks like you will need to remove or reconcile the conflicting FormIDs in one or the other. Just changing the flag would not affect the doubling up if I am interpreting correctly on Nexus.

I haven't run LODs for the fog yet. I did read a conversation in the nexus comments for that mod where people seemed to be pretty confident that just removing the flag will allow the tweaked mod to overwrite the fog from OW. I dunno, they may be wrong, therefore I am too... I can always undo it, disable OW and run just the fog to see if it fixes the problem, and then come up with a complete solution.

[Hypobolic]

Okay, finally got around to running LODs with the alternate Obsidian Fog recommended above.

No go. The problem is still happening.

I initially did try to run both the modified mountain fog and Obsidian Weathers at the same time hope one would overwrite the other, but they just doubled up. Anyhow, I then just disabled OW complete and ran the modified fog alone and the problem was still there.

I dunno, I think I'll might try running some other weathers, or even the vanilla Skyrim fog and see what happens. It could just be a limitation of the engine, or a side effect of the all of the mods I have running that LOOT doesn't catch. Of course it would be great to actually find a fix for this.

I'll return with whatever I discover in my experiments next.

[Hypobolic]

Okay, update:

I decided to go all the way for this test and remove as many possible variables as I reasonably could. Skyrim SE v1.5.97 , no mods except for ENB and a few dlls that can't be managed by MO2, guess what:

It happens in Vanilla too!

So, this is some sort of engine bug happening, likely in the native code. Anyhow, It's super easy to reproduce, and actually I'm going to lay out the step here in case any intrepid modder feels like tackling a challenge (likely not every single one of these steps is necessary, but I'm including them for posterity):

1. Vanilla Skyrim SE v.1.5.97
2. Set launcher graphics settings to Ultra, borderless, windowed. 1440p (I just put resolution here because that's what I'm running at. Yes, I've made bug reports before!)
3. Launch the game and in the console type 

   coc riverwood

4. Wait for three hours (T key)
5. in the console type 

   cow tamriel 40 -24

6. You should now find yourself on the Rifen docks.
7. In 1st person, turn your view towards SSW (I could give an exact vector, but I don't feel like trying to figure out and fiddle with the getangle command right now)
8. Pan the yaw of your camera over the trees on the other side of the lake. Pay attention to the mountains in the upper right of the screen. If you hit the correct angle, the exact patch of fog shown in my screenshots above should pop in and out like clockwork.

Now, there is a small chance that some of the .DLLs that in my skyrim root directory could be causing this, but I find it unlikely. 

Anyhow, there's the short of it, and, well, the long of it...

Edited August 20, 2022 by Hypobolic

[DoubleYou]

Yeah, I briefly tested the other day and saw this issue with our setup. Can't say I ever noticed it before.

[Hypobolic]

So, I was wondering what I can actually do about it at this point. I know that the USSEP guys take bug requests, but they don't actually deal with SKSE native bug right? I could submit a bug report to them and see what happens.

I did post a comment on Skyrim Engine bugs and Fixes, to the host/author there. Seems to be something more in line with the work done on that mod.

This is not world ending stuff, just immersion breaking for me, at least with ENB and Obsidian fogs installed it's a lot more noticeable. I've dabbled with just installing mods many times over the years, but I'm taking a really deep dive right now and have a couple of small ideas I'd like to work on. So I guess I'm saying that since I find myself getting more involved, I'm curious what to do when I come across a 100% repo issue like this.

 

[DoubleYou]

Nah, you're going about it wrong. This isn't an engine bug. Pretty sure this is cut and dry simple z-fighting. There are several ways you can try and fix that. 

• Modify placement
• Modify mesh
• Probably other ways too

Wouldn't be surprised if someone else hasn't already fixed it.

[Hypobolic]

Okay, well I'll keep it on my list of things to look into as I get more comfortable with the dev environment for SSE. I finally got my build finished (yeah right!) and compatible and want to play a bit.

Also, I've done countless google searches on this issue and have definitely come across people reporting the same problem but the very few solutions offered haven't worked. The most common one I've come across is to set 

 [Display] fNearDistance=13.0000

But that has zero effect on this problem for me, though some people report it helping, I wonder if they're actually just talking about actual mountain mesh/texture z-fighting and not the fog clouds. It's hard to tell.

[DoubleYou]

Adjusting INI settings is only going to mask this problem. It is better to fix issues like this at the source, which is how your journey as a mod author begins.