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Holger

Crashes during late fall/early spring with add-on mesh

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Hi all:you might have heard about (or experienced yourself) strange FS9 crash-to-desktop errors at certain airports that only happen during the transitional seasons (when patchy snow appears on the ground), e.g., since Nov 21. These CTDs have been reported by users of add-on meshes, such as FSGenesis and LAGO, at airfields in Europe and North America. It turns out that at least one of my add-on mesh files (bcmesh9d.zip) triggers this type of CTD, at Castlegar. If you have that file installed, try starting a flight at CYCG between Nov 21 and Dec 21 during daylight hours and you'll see what I mean.Earlier today, I managed to fix the same type of error for Sion, Switzerland (LSGS). However, trying to do the same at Castlegar has proved fruitless, so I hope someone has more knowledge or better ideas...Based on my success with Sion, I can tell the factors involved:1. the patchy blended snow textures that only occur during late fall and early spring2. the airfield's default airport background polygon (apron) file (AB9****0.bgl)3. the add-on mesh4. certain landclass textures in the vicinity of the airfieldThe crashes don't occur when the add-on meshes or the local AB9*.bgl file are deactivated. Deactivating the airport's flatten (FL9*.bgl) or buildings (AP9*.bgl) has no effect.My reasoning is that, while an airport itself is flattened by a LWM flatten polygon (FL9****0.bgl), perhaps the apron (AB9****0.bgl) extends past this polygon in places. Add-on meshes often change the slope of the transition from the airport's elevation to the surrounding terrain; maybe it's in these areas where the textures (landclass, apron, and snow textures) clash. In Sion, all it took to stop the CTDs (well, after lots of trial-and-error!) was a small patch that overwrites the default landclass, specifically all class #55 (mixed forest on very light ground) with another type (I used #24, mixed forest). The patch file, including a more detailed description of my process, are available in this thread (on page 3): http://portal.fsgenesis.net/index.php?name...viewtopic&t=350No such luck in Castlegar. Again, deactivating add-on mesh or AB9*.bgl stops the CTDs. But none of the landclass replacements that worked in Sion have provided any positive results. I've tried various classes, forested, bare (with and without autogen), as well as one class over the entire area, or a mix. Crash after crash. Also, I've tried it without any of my additional scenery enhancements (roads, bridges, VTP2 polys, etc.) and with autogen off. Didn't matter.I even tried excluding the apron in Ground2K4 (layer #7). Apron was gone but not the crashes.Below are two images of the Castlegar area that might help with debugging. The first one is a shot of TMFViewer with the add-on mesh and the AB9*.bgl; both files together, in conjunction with the season and (perhaps) the landclass, trigger a CTD. Looks like a pretty innocent little polygon, doesn't it?http://forums.avsim.net/user_files/49926.jpgThe second image is taken on approach to Castlegar, on Nov 22. It's at 3x zoom and fuzzy because, as soon as the mesh and textures sharpen, the crash occurs. Notice the white patches of snow that reach into the apron and also the steep drop-offs at the edge of the flatten poly to the right and front. I don't know whether they play a part.http://forums.avsim.net/user_files/49927.jpgAny fresh ideas are highly appreciated.Cheers, Holger

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Hi Holger.I made a large mesh of the area from STRM3 arcsec mergerd with SRTM30 data.Same thing! crashes according to the ground textures present.I'm thinking this is a bug in the sim, or related to the textures somehow. Slopes do change some textures, and we are changing the slopes with the mesh. That might reveal the answer.Dick

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Hi Holger,I had the exact same problem a little while ago. I thought it was the XP bugfix for GMax. I was wrong.Turned out it was a replacement overlay texture used for railroad tracks that I'd downloaded.The seasonal thing tells me its got to be a texture.Good luckJohn

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Hi allFor me excluding the apron with defarea(layer #7)works fine in Sion,crashing with lago mesh,and also with Gauthier swiss airports.The bug is the same near my town, in LFNA,even without any mesh or add on,that can be solved also with a very little flatten .Guy Nemoz (french altiports) founded these solutions.Daniel

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Hi Holger.My mesh will not even allow the FLT to load ( stops at 56% ). This is without your terrain in use at all! Just my mesh and the default BGLs.If I remove the AB916140.bgl, it will work.ORIf I remove the AP, FL, and HP916140... then I can use the default AB916140.bgl.This seems to indicate a conflict with our mesh, and the way flattens ( mesh alterations ) adjust that mesh, and the textures applied over that adjusted slope. This is a bug in the sim.I tried the mesh in different folders, and even tried it in the default "worldscenery" folder... no difference. It's date related due to the snow.Cures?Maybe different textures in the AB file ( I can try that tonight with a hex editor or decompiling the AB ).We are at a loss to explain it because of a lack of SDK info. Some things have changed in FS9, and maybe mesh is one of them.Dick

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Hi Holger.Here's what I can find:The Airport Background textures are configured by "terrain.cfg".In that file, under the " Airport Backgrounds" heading, the numbers for the various backgrounds are given, along with some pertinant info.ALL or the APBs contain a line:MaskClassMap=2The next section is " Parks" and they all contain a line like:Textures=135 ( under Golf Course ) and landclass value for Golf Course is '135'.I commented out all the masking lines in the APB section as: MaskClassMap=2and then added apropriate landclass textures like so:[Texture.1194] // Sand DesertType=1Size=4ExcludeAutogen=1// MaskClassMap=2Textures=050'050'is the landclass for Sand Desert.The result? No sim crashes... also no snow blending. They just show straight landclass.This produces a runnin sim, but looks odd:[Texture.1194] // Sand DesertType=1Size=4ExcludeAutogen=1MaskClassMap=5===============Next, I'll check a much lower LOD mesh.Dick

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Howdy,Daniel, that's interesting that the layer-7 exclude works. I didn't try it in Sion but did in Castlegar without success. However, if you exclude the apron you'll end up with autogen all over the airport unless you pick autogen-free landclasses for that area (or code lots of tiny excludes). Or, is that not a problem at the airports you fixed?Dick, thanks for checking into that - much appreciated! Meanwhile, I tried an external flatten switch to make sure that the entire area covered by the AB9* polygon is perfectly flat; alas, the CTDs kept coming. What I haven't tried is to extend the flatten across all LOD13 vertices that might influence the airport. However, that wouldn't work in Castlegar because of the nearby Columbia River.Cheers, Holger

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Hi Dick,crossing posts ;-)It never occurred to me to check the terrain.cfg - great find! I'll try to reproduce your approach.Thanks,Holger

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Hi Holger.Why not try that flatten just as a test? It would be helpful if we could confirm this as a slope problem rather than just the AB alone.I tried meshes of different LODs... LOD6 is OK, but I suspect the area is already LOD6, and the addon mesh just isn't getting used.The next area to test might be different landclasses surrounding the AB area, to see if they mask differently or also crash the sim.Dick

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Hi Dick:I'll try a big flatten at Castlegar but that means I have to disable the default (or my add-on) river LWM.If you'd like to test your LOD6 add-on mesh, you could try it with demusac6.bgl in fs2004sceneryworldscenery disabled. As for the landclass, I have tried several different types in a 6 (N-S) by 3 (W-E) cluster of areas surrounding CYRV. Specifically, I've tried forest classes 3 and 24 (which both stopped the Sion CTD)), as well as "barren" classes 2 and 42. I tried them as single classes and in mixed configurations without success. One other thing to consider is the TMVL setting. My Sion fix (see link above) does not work if TMVL is set to higher than 20; so there's definitely a mesh influence on the CTDs. Cheers, Holger

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I have came across this problem too when using a high resolution (not that high, just LOD8) mesh with my VTP/LWM scenery. In certain seasons, FS would crash to desktop. Some users also reported these problems when using my mesh (but not my VTP/LWM scenery which I haven't distributed yet). One thing that helped in SOME cases was to put the add-on meshes together with the default ones, in 'scenery/world/scenery' inside the FS folder. Having a bigger LOD they will take precedence over the default areas anyway, so they still work OK.

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Hi Holger.I think I found it.MS built an airfield called "Trail" ( CAD4 ).It cannot possibly be real, if you look at it in the sim. It is in an adjacent VTP Cell. That cell contains 2 VTP polys... but the poly of this airfield causes the sim to crash during on November 21.I decompiled the AB916140.bgl, commented out the VTP code for that poly, recompiled, restarted the FLT of November21 near Castlegar, and the crashing is gone. my real process for finding it was to eliminate blocks of VTP cells in the decompiled code, untilI found what was causing the crash. The VTP code is actually alright, but the slope of the airfield's flatten must goof up the texture rendering.The good news is a Layer7 VTP2 exclude will solve the problem without requiring a replacement of the the default BGL or fooling with the terrain.cfg file:;--------------------------------------------------; DefArea 2.0 for FS2004 : Generated on 11/24/2003 6:52:17 PM;--------------------------------------------------include TDFMacros.incinclude TDFHeaders.incBGLHeader 50, 48, -116, -118, TerrainHeaderStart, VTPHeaderVTPHeader label word VTPFileHeader 256, VTPIndexStart, TextureStart, VTPEndVTPStart label word datamark_v0 label word VTPDataArea 1, 0, 3, 13 VTPLayer 7, 1 VTPNumTexturesInLayer 0, 0 VTPDataArea 1, 0, 3, 14 VTPLayer 7, 1 VTPNumTexturesInLayer 0, 0 datamark_v1 label word;----------------------------------------------Cellv_133_116 EQU VTPCellID 0, 133, 116;---------------------------------------------- VTPIndexStart label word VTPIndexHeader 1, VTPIndexData, VTPStart VTPIndexData label word VTPIndexEntry Cellv_133_116, VTPStart, datamark_v0, datamark_v1;-----------------------------TextureStart label word VTPTextureListHeader 1, TextureIndexStart, TextureDataStart, TextureDataEndTextureIndexStart label word VTPTextureListEntry TextureDataStart, texturemark_0, texturemark_1TextureDataStart label word texturemark_0 label word VTPTextureName "1162" VTPTextureType 2, 0, 0, 4 texturemark_1 label wordTextureDataEnd label word; ------------------------------VTPEnd label wordThis used DefArea2 from Christian Fumey. Try it to confirm this is the fix.I'm attaching the code and the BGL as a zip file.Dick

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Hi Dick:geez, I can't believe I was trying to fix the wrong airfield :-doh I had this nagging suspicion that I wasn't in the right place, especially after the layer-7 exclude didn't work in CYVR. I just assumed that the next AB* poly (Trail) was too far away to be fully loaded when approaching or starting at Castlegar.Thanks for the fix; I'll try the code and let you know.Trail airport does exist indeed, only not quite where FS placed it: http://www.globalairphotos.com/gallery/BC/Trail/All/2003/6 (load the center image in the large version and you can make out CAD4 in the top right; the camera is facing E to SE. In my first version of the high-res mesh for the area, bcmesh9b.zip, I actually moved the mountain to the north (per hand-edit in Microdem) to carve out a bit more room for the airport.I also didn't realize that BGLAnalyze can decompile AB9*.bgl files.I assume the exclude means that we now have lots of interesting autogen things scattered across CAD4? In other words, any of these fixes will have to include local landclass updates.Anyway, thanks again for taking on the challenge and solving it so quickly - you da man!Cheers, Holger

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Howdy:just a quick confirmation that your patch does work on my machine, too. I only tried it with my LOD9 mesh and scenery updates installed but will check out the FSG and default meshes later.Here's Castlegar on Nov. 22; at least my effort wasn't all wasted; I moved the golf course to its proper place and added a few more roads and utility lines while barking up the wrong tree ;-) http://forums.avsim.net/user_files/50096.jpgAnd here's post-fix Trail, which now is an even more challenging approach than it already was. Next I'll have to figure out a suitable landclass replacement for the area, which, perhaps, might make the layer-7 exclude unnecessary.http://forums.avsim.net/user_files/50097.jpgAnyway, it would still be nice to know why these CTDs occur! For example, how are these patches of snow blended in? Is there a special mask somewhere, like the ones for the edge-blending of landclasses? Also, I noticed that flight loading time increases during these transitional season, so the blending seems to require some extra time.Cheers, Holger

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