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Cloud Flickering In Mountains

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Hey Guys,


I know this has been the topic of more than one thread - I have read many of them now - but I haven't found a solution.


I have seen this fix and tried it: 



This fix has been around for several years and works:  Go to this folder:


There you will find a file called SwarmCloud.fx. Make a backup copy of this file .

Open the original SwarmCloud.fx in notepad or wordpad and then look down about 20 lines down from the top. You will see this entry:

bool NewMaterialUsage = true;

Change its value from true to false. Make sure to keep the semi-colon.

Save and close the file.

Now, go to C:\documents & settings\<your username>\Local Settings\Application Data\Microsoft\FSX\

(If you can't get to this folder make sure that "show hidden & system files/folders" is turned on in your windows folder options.)

(This is the XP path by the way, Vista users will have to hunt for their equivalent in the users folder.)

You will see a folder there called: Shaders.

Either move that folder out of there or delete it. Don't worry, FSX will build a new one the next time you run it. It contains a cache of the compiled shaders. This folder must be removed to ensure that the change you made to the cloud shader file above will be compiled and used on FSX's next run.

That's it. Run FSX and enjoy very solid and reliable clouds! I haven't seen any other bugs or oddities crop up from this change. I've had a few friends who were also experiencing flashing clouds test it as well, one on nvidia, the other on ATI, and their clouds stay perfectly put now."

Kind regards,




I use ASN and REX4 along with DX10 and the fixer.  I noticed that ASN automatically changes the Swarmcloud.fx file as above. 


I've tried jacking up my water quality, that didn't work either.  All my clouds look fantastic until I get into mountains (which I fly in all the time!)  It's a real immersion killer, everything else is running so well!  

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That fix is for popping cloud. Not the cloud flickering mountain tops. As2012 was quite good for eliminating the effect by raising the lower cloud level to 9000ft. Not sure you can do that in ASN.

To never see that again, you would need to change to P3DV2

System: MSFS2020-Premium Deluxe, P3D 5.0, ASUS Maximus XI Hero,  Intel i7-8086K o/c to 5.0GHz, Corsair AIO H115i Pro, Corsair Spec Omega Case,Nvidia GTX 1080 Ti 11Gb, Samsung 970 EVO M.2 SSD, 1Tb Samsung 860 EVO SSD, 32Gb Corsair Vengeance DDR4 3200Mhz RAM, EVGA 850+ Gold PSU,Win 10 Pro 64-bit, Samsung 43 UHD TV, LG 43UD79 43" 4K IPS Panel., Airbus TCA Full Kit, Logitech/Saitek Flight Yoke System, Multi, Radio, Switch Panels,Stream Deck XL.


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As far as I know, there's no solution for this, unfortunately. Yeah, it's really annoying... 

Oh, about the "0" views, this is a forum bug -- the views of a topic only show up when someone makes a post.

Gabriel J. T. Rodrigues

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Well damn..  there's really no fix huh?


I have P3DV2 but, as it stands right now, I just don't get nearly the smooth and stable experience I get out of FSX. 


If it wasn't for this cloud problem, it would be close to perfect. 


Thanks for the replies though. 

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If you use the FSX default weather you can:


1.) Under Current Weather click *Change*


2.) Click *User Defined* -- then click *Customize*


3.) Then click *Advanced* -- set *Tops* to 18000 and set *Base* to 15000


This works, but as I recall there are some weird shadows(?) as a result. It's one of the basic FSX flaws. They didn't get the elevation right and the clouds are conflicting with the mountains. Here in CO the mountains get as high as 14500 and they are tickling the clouds in FSX!!! So to speak.


This probably won't work with a weather program though. I use ASN and there are still some jittery clouds so maybe I'll try it???

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there is no known solution for clouds flickering when intersecting with mountain edges. It's absolutely show-stopping; I fly near the Alps and sometimes it gets so bad my eyes bleed. Only real "solution" is to manually set your cloud base higher than max mountainous terrain altitude in the area you are flying, so the clouds are always above the highest peak.

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