Hey guys. I know a lot of people have been experiencing flashing clouds since SP2 and Accel came along, where entire sections of clouds will just blink out for a few frames and then return, particularly around cities or airports. It's pretty annoying and has put an enormous dent in my FSX video work, ruining shot after shot.So after an *insane* amount of investigation and testing I figured out that this was caused whenever high polygon objects come into view, such as unique buildings, jetways, aircraft carriers, marinas etc, especially those contained in the files that make up the global scenery layer. This occurs primarily with Nvidia hardware but on older ATI cards as well.Anyway if you are experiencing flashing clouds and they have been driving you as nuts as they have me (equivalent to two pieces of styrofoam being rubbed together :)) then read on, I found a fix:The ultimate culprit lies in the material handling of the cloud shader.Go to this folder:FSXShadersHLSLmiscThere you will find a file called SwarmCloud.fx. Make a backup copy of this file somewhere. (as always no crying if you don't do this step) :)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 & settingsLocal SettingsApplication DataMicrosoftFSX(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 equivlalent 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.Six days of work to come up with this simple solution, ugh. I mistakenly came at it from the scenery angle thinking it was some kind of texture conflict, guess I enjoy taking the long way around, hehe. On the upside I now know a ton more about FSX's scenery and memory management than I ever wanted to. :) I've also seen a big reduction in the stupid black square thing on the beacon lights and vasi etc, could be related, not sure. Eradicating that is my next challenge.Disclaimer: I have only tested this on DX9 under XP pro 32. I have no idea if there will be any difference in behaviour on Vista or under DX10, hence the backup. ;)Cheers,-mike

Mike,You are the man!Thanks so much for investigating this issue. I'm amazed at how much you know about the internals of FSX; and I've been fighting this very issue as well because it's been mucking up some of my own work.Don't know if it's just me, or if it's relevant. But when I went searching for the Shader cache in AppData, I could not find it, even with hidden files viewing. However, if I did a search for it, it showed up and I could delete it from the search explorer.I mention it in case you get questions about this.I've implemented the suggested fix and will report back if I notice any anomolies with it.Cheers,Kevin

I also make professional videos using FS and this problem has, like you, driven me NUTS! I can't begin to count the number of re-takes to get a shot correct.I just tested this with every kind of weather and cloud I could find and WOW! I can't imagine how you found this, or the time and trial and error it took, but let me just say, if you ever make it to West Palm Beach, steak and lobster is on me!GREAT find! I have saved this so I never lose it, Thank you !

Bookmarked! Can your genius do something about the visibility layer flashing? We'll get to some more fixes later :-hah Thanks!Regards, Kendall#1: [email protected]/Coolermaster HyperTX2 Gigabyte P35-DS3L 4GB Crucial Ballistix Tracers PC6400 Seagate 250GB 7200.10 SATA2 Gigabyte X800XT -Cat 6.12's CH Yoke/Pedals/Saitek Throttle Dual Monitor: Dell 2405/1905 #2: Dell 8400 3.2 H.T. 3GB PC4200 Diamond Xtreme/Logitech X-530's

Haha! The visibility layer issues probably are best addressed by the master himself, Pete Dowson, but I might have a look at that as well. I just attack any problem that gets in my way, and this one's been in it for months. :)Glad it worked for you guys!(PS: PPSFA, I'm allergic to shellfish unfortunately but I'll happily accept the steak! :-))Cheers guys,-mike

Kevin, might want to just double check which Appdata folder you were looking in. There are two. One of them is Docs&settings/username/application data, where the fsx.cfg is located etc, and the other one is Docs&settings/username/local settings/application data. That second one is where the shader cache is stored. A bit confusing I know.EDIT: Now that I think about it, if you installed FSX for "all users" then that user folder is where the shader cache would probably be.Cheers,-mike

Mike,I found it here:Documents and Settings/username/local settings/application datarather than here:Documents and Settings/username/application dataPutting the following in the interests of complete documentation: I immediately began noticing anomolies with some of the default scenery in a mission I was developing. So, this fix may not be totally without negative effects.Clouds are definitely behaving now though. I will keep investigating this and update as soon as I figure out what's going on with some of the scenery in my mission.

Hey Kevin, yup that's where they would be. I haven't noticed any scenery issues since at all after the change and I've flown all over the place checking my default and addon stuff. If you let me know which scenery objects are complaining I could drop them in with the mission editor myself and have a look. Can send me a pm here if you like. Either way I hope it works out.Cheers,-mike

-Nice find Mike- !... I will pass this on and credit you with the findOne thing.. You should not need to delete the -entire- shader folder.. just the MISC folder as it contains the SWARMCLOUD.fx shader file. However deleting the entire shader folder should not hurt anything as you pointed out it is rebuilt on boot.

Hello,Does this also works with ASX and AGX?Thanks in advance

In Vista:After changing the file details as above,Try renaming...C:UsersVistaAppDataLocalMicrosoftFSXShadersMiscSeems to work perfect Vista 32 DX9, what a great fix, thanks!!!

This should be stickied in the "FSX Tweaks" forum!--James

Kevin you might be right about some side effects.I've noticed two small things that may be drawbacks to my tonic haha. After some further testing on my machine I've noticed that some global scenery objects are coming into view in their highest LOD, things like port cranes etc, so in places like seattle with lots of those the fps may tank a bit. That may explain some of the oddities you mentioned with your mission scenery, stuff from the global folder.Also when multiple layers of cumulus clouds are close together there seems to be a bit more 'bleed through' than usual, not that FSX was particularly good at this to start with haha. ASX users who try this change will probably notice that more.If anyone can confirm those possible side effects I'd appreciate it.I'll keep on messing with it, but at least for me those are pretty minor drawbacks compared to swaths of clouds flashing in and out of the scene.Cheers,-mike

I tried this, although with SP1, so that may be why, but while it helped the cloud situation, I was flying through fog last night, and was getting some weird effects. Like a sharp division of the screen between light and dark tones of gray. I backed it out and all was normal again!!

>This should be stickied in the "FSX Tweaks" forum!>>--JamesYes indeed, great fix, that flashing was very annoying.