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Guest luissa

airport elevation. i'm missing a step!

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HiI am making an afcad for Kai Tak (Hong Kong Old vhhx) airport for the Hong Kong 2004 scenery.At first all AI were sunk under the airport, but I decompiled the default airport .bgl file and inserted the correct elevation.Now the departing AI are on the tarmac, but landing aircraft still sink under the tarmac.I have tried adjusting the default airport (both the airport data and the runway data) and the afcad2 file to all sorts of elevations, but landing AI still insist on sinking under the airport.I've tried decompiling the HK2004 scenery .bgl's, but the all come up as invalid facility files which can't be decompiled.Any ideas what other elevation data I should be adjusting?RegardsGraeme

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Hello Graeme,That is a very interesting solution that Peter discovered, although I am not sure that I understand it completely.Perhaps there is another possibility. As Lee Swordy mentions in the AFCAD doumentation, an AFCAD file will not change the airport default altitude. For this to work, the Flight Simulator Development Team will need to add a Delete Altitude command for the Airport section.You did the next best thing, which is to decompile the AP file and correct the altitude there. This changes the altitude of only part of the airport, though.The runway altitude is not included in this file, but in the corresponding FL (FLATTEN, I suppose) file. You can also decompile this and modify that altitude (and the FS Team might consider a Delete Flatten command as well, which would be very helpful.)Supposedly, it is possible to use a Flatten switch (either the old Area 16N or the newer L/WM flatten), but I have not yet been able to make those work correctly. Steve Greenwood provides utilities for this, although you can also use any scenery design program if you wish.Best regards.Luis

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Peters solution, which is to put a copy of the same afcad into the scenery/world/scenery directory, tricks the sim into thinking this is the default scenery height. Very clever..and it absolutely does work. I had to use this trick to add AI to a number of Georender airports.Just follow it step by step and it does work.Eric

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Excellent thanks.Now how do I get the AI to take the proper famous approach to runway 13!?! I have read it can't be done. Not sure if this is still the caseOne final issue that I ignored at first. The front wheel of the AI aircraft is perfectly on the tarmac but the rear wheels are slightly in the air!RegardsGraeme

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Thank you, Eric. I understood what Peter was recommending, but not exactly how it is supposed to work.You say that it "tricks" the game into using the new AFCAD file, but what exactly does that mean? How does one go about tricking the scenery engine? It sounds, rather, as if this method is creating a conflict between the default AP file and the new AFACD file. Conflicts are never a good thing, particularly in Flight Simulator, so this all sounds very suspect to me.Also, Peter gives an explanation of what he claims is happening within the simulator while all this is going on. I have read many of the Microsoft technical documents, though certainly not all, and have never come across such a description of the inner workings of FS. So, I wonder how Peter came up with it all.On the other hand, we know that the FL file contains the airport flatten with the elevation, and it is easy enough to modify and recompile this file. Here is a modification of the island of Saba (pron. say'-bah) that came without mesh. The default airport is set to an elevation of about 15 feet when it should be 104 feet.http://forums.avsim.net/user_files/102029.gifhttp://forums.avsim.net/user_files/102030.gifWithout modifying the FL file, the new airport would wind up in an ugly 90-foot deep trench on that plateau.Modifying the FL file and distributing it is NOT the same as removing some parts of the HP file and distributing that, because if the scenery is ever uninstalled, the FL still contains information for that airport.Anyway, while I do not doubt that you are getting results with Peter's method, perhaps it would be better for the creators of the Georender scenery to approach this problem differently, or even to just not attempt to change the elevation of the default airport scenery, if they do not want to distribute modified FL files.Best regards.Luis

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Edited - after writing this I remember that I addressed this question in the past. Searching the forum I found this:http://forums.avsim.net/dcboard.php?az=sho..._id=15891&page=Hello all,This is very interesting. Here is my experience on this. When I, and friend, designed "Porto Santo" airport (LPPS) we need to correct to altitude of the default runway. The default was 110 m and we would like to bring it down to 100 m. We did not make the runway with AFACD. We did it with the "FS2002 SCASM runway command". So for the visual scenery;:1) we made a flat polygon around the airport with an altitude of 100m2) we made the runway with an altitude of 100mThen we used AFCAD to define the trafic paths. We made an LPPS_AFCAD.BGL with everyting related to altitude equal to 100 meters. This LPPS_AFCAD.BGL was placed in the local scenery folder.Everyting was almost fine. We could land at LPPS with our aircraft arriving nicely with the wheels on the ground as other incoming AI aircraft. The only problem was when we used "GoTo Airport". When we get there were 2 or 3 AIs where floating 10 meters in the air!!!Now that I read Peter's trick I understand the problem completely and I see that there is a simpler solution than the one we found at the time. In fact we knew that those floating aircrafts were due to the default AFCAD.BGL (the only place were the 110m still existed). So we opened the default AFCAD with an hex editor and we tried to change the default altitude of the default AFCAD.BGL. We were lucky. But today I see that I could simply copy the local LPPS_AFCAD.BGL to the default folder and that was it!Regards and an Happy New Year to all readers of this forum!Luis

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I tried putting a duplicate afcad in the scenery/world/scenery folder, but the landing AI still sank into the ground. I also tried putting it in the HK2004 addon scenery folder (which is the one I am interested in) but this did not work either.Where can I find the corresponding FL file (for Hong Kong Old) so I can try adjusting the elevation in there?Thanks for the advice so far.RegardsGraeme

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Hello,I do not know if YOUR aircraft also sinks. The previous observation of one wheel OK and other NOT, is also very strange. In order to locate the flatten consider this:- if you place a flatten polygon which "contains" (is larger than) the default flatten, then you do not need to edit the FLXXX.BGL file. Just make a flat polygon and place it on your local SCENERY folder.In order to locate the FLXXXX for your region, may be this helps:Default LWM files for Western Europe, for example, are located in the folder:C:Program FilesMicrosoft GamesFlight Simulator 9SceneryEurwSceneryDifferent regions of the world will be located in different folders like Eure for Eastern Europe, Afri for Africa, Name for North America (East part) and so on.Inside these folders you have several files. The following files are LWM files:FL9XXYY0.BGL - these files refer to flatten polygons HP9XXYY0.BGL - these files refer to hydro polygons (and/or hydro area fills) All LWM files cover a complete LOD5 square. The XX and YY appearing in the filename refer to the X and Y coordinates of the LOD5 square to which the file refers to. In order to know which file applies for a given location you look to the LOD5 coordinates that appear in the status bar when you have the mouse in the desired position. In the south of Portugal, for example, the satusus bar shows LOD5 45 18. Therefore if you want to load the hydro LWM data for that region you look for the file HP945180.BGL. Note that there is a leading 9 and a trailing 0 in the sequence of digits that define the location.Regards, Luis

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HiI'd found the FL file, but can't decompile it with Alessandro Antanini's bglxml, found here on avsim. It says there is no valid facility data. I'll try emailing flightsoft too, as they are the distributors for HK2004, to see what they can suggest.I'm going to go back to flying for a while!By the way, I have since noticed the 'leaning forward' AI I have are restricted to a certain make and not all AI, so I'll have a word with the creators.Graeme

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Hi Luis.The problem seem to be that the aprons default to the elevation of the first encountered instance of an airport. Duplicate files may be the answer, as Peter found. I made a new project folder called "AFCAD_Elevation_Corrections" with a "scenery" subfolder. Copies of AFCADS for the purpose of correcting elevations can be placed there. The project folder can then be added in the Scenery Library, and moved down under the regional scenery folders in the Library List:http://forums.avsim.net/user_files/102088.jpgNote that I also placed the FS_USGS landclass Folder below the regional scenery folders... there is a problem with landclass display that means they should be below the regional sceneries ( loaded before LWMs and VTPs ).This folder setup is a bit neater than throwing the correcting AFCADS into the 'WorldScenery' folder.The airport background still needs a flatten ( LWM or Area16n SCASM ) to the correct height. The worst of this work-around is that if you get rid of the AFCAD, you must remember to get rid of the correction as well!!!Once again, I plead with the FS design team to insure local addon scenery have a priority over mesh and flattens, allowing us to return a small area to the mesh-state regardless of the previously loaded LWM ( and airport ) elevations.Dick

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Graeme, I do not advise modfiying the default files, but since you are already doing this, then please get Jim Keir's LWMViewer, as it will make it all very easy.Thank you for testing this, Dick. This entire situation seems a real mess, but at least keeping third-party files out of the World/Scenery folder is somewhat better.I have been giving some thought to all this business of releasing scenery with modified hyp files. You and I see all the pitfalls, and every week there is at least one user who posts a sorry story of squared-off coasts or shorelines far from land.What most aircraft or scenery designers do not take into account is that a great number of users download a package only to take a quick look, maybe to fly around a little, and then delete it. The excellent packages like Holger's scenery are rarely removed (although he has gotten some of those as well), but many other packages of lesser quality have a shorter life and are destined to be uninstalled.Since I have not yet seen this kind of scenery modification that includes a clear and comprehensible description of the problem for the user, explaining why they should particularly remember what was changed in the default files, it is not surprising that there should be problems. And there will always be problems with this type of modification.And changing the FL files will just lead to the same problems. Even if one places a duplicate AFCAD file as above, the airport flatten in the FL file will not reflect this modification.We can only hope that our New Year's present from the Flight Simulator Team will be some way to override or exclude all the elements of terrain, in the same way that we can do this with objects. It is already possible to do so with much of the terrain, such as VTP lines that can be excluded, or L/WM that can be covered with another (except for the flatten, of course.)Very best wishes to all for the New Year, much health and prosperity to all.Best regards.Luis

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Before I forget, let me just mention that Jacky Brouze has repented and is once again offering his wonderful utilities to the general community. Un grand merci, Jacky! Although I certainly understand why he was so upset.Anyway, try his JABBGL - this very easy to use program allows for modifying the altitude in the default AP files.Best regards.Luis

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Hi all,Regards and a Happy New Year to all readers of these avsim forums and also the effective warning systems against the tsunami for all people living around the oceansVlada Stoje

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HiThanks for help so far. I'm getting a bit confussed now, so to recap here is what I have tried, and the landing AI still sink.1. Placing duplicate afcad in scenery/world/scenery2. Placing duplicate afcad in the offending add-on scenery folder3. placing duplicate afcad in a new folder scenery/corrected_elevations/scenery, and setting this below the default scenerys in the scenery library4. Elevation of runway and airport have been reset in the APxxxxxx.bgl file (This successful placed departing AI at the correct elevation)I have downloaded LWMviewer, and it shows 2 additional files effecting the area, the FLxxxxxx.bgl and the ABxxxxxx.bgl. Trouble for me is I don't understand the data it exports as there is nothing that obviously says elevation. Is there a tutorial somewhere for deciphering the code that lwmviewer creates?Here is the data for the cell from the FL file that effects my area;; Start of cell 627 x 192 dataCELLSTART_000001 label wordCellID_000001 EQU LWMCellID 0, 0, _Transparent_, 627, 192 LWMDataAreaDrawPolygons 1,_Flatten_,1,11,5 LWMPoly3 4, 0, _Water_, 15, 30, 15, 30 LWMPoint3 64, 136, 0 LWMPoint3 73, 110, 0 LWMPoint3 255, 196, 0 LWMPoint3 255, 226, 0 LWMDataAreaDrawPolygons 1,_Flatten_,1,12,5 LWMPoly3 4, 0, _Water_, 15, 30, 15, 30 LWMPoint3 1, 226, 0 LWMPoint3 1, 196, 0 LWMPoint3 126, 255, 0 LWMPoint3 62, 255, 0 LWMDataAreaDrawPolygons 1,_Flatten_,1,12,6 LWMPoly3 4, 0, _Water_, 15, 30, 15, 30 LWMPoint3 62, 1, 0 LWMPoint3 126, 1, 0 LWMPoint3 134, 5, 0 LWMPoint3 126, 31, 0 LWMDataAreaDrawPolygons 1,_Flatten_,1,19,15 LWMPoly3 8, 0, _Water_, 0, 0, 0, 0 LWMPoint3 211, 95, 0 LWMPoint3 241, 134, 0 LWMPoint3 241, 97, 0 LWMPoint3 230, 65, 0 LWMPoint3 255, 51, 0 LWMPoint3 255, 255, 0 LWMPoint3 132, 255, 0 LWMPoint3 114, 231, 0 LWMDataAreaDrawPolygons 1,_Flatten_,1,20,14 LWMPoly3 4, 0, _Water_, 0, 0, 0, 0 LWMPoint3 43, 249, 0 LWMPoint3 81, 233, 0 LWMPoint3 95, 255, 0 LWMPoint3 44, 255, 0 LWMDataAreaDrawPolygons 1,_Flatten_,1,20,15 LWMPoly3 11, 0, _Water_, 0, 0, 0, 0 LWMPoint3 48, 24, 0 LWMPoint3 44, 1, 0 LWMPoint3 95, 1, 0 LWMPoint3 97, 4, 0 LWMPoint3 100, 174, 0 LWMPoint3 57, 228, 0 LWMPoint3 29, 195, 0 LWMPoint3 17, 250, 0 LWMPoint3 23, 255, 0 LWMPoint3 1, 255, 0 LWMPoint3 1, 51, 0 LWMDataAreaDrawPolygons 1,_Flatten_,1,0,16 LWMPoly3 4, 0, _Water_, 5, 101, 5, 101 LWMPoint3 1, 216, 0 LWMPoint3 255, 107, 0 LWMPoint3 255, 255, 0 LWMPoint3 1, 255, 0 LWMDataAreaDrawPolygons 1,_Flatten_,1,1,16 LWMPoly3 8, 0, _Water_, 5, 101, 5, 101 LWMPoint3 255, 83, 0 LWMPoint3 255, 255, 0 LWMPoint3 1, 255, 0 LWMPoint3 1, 107, 0 LWMPoint3 223, 11, 0 LWMPoint3 232, 14, 0 LWMPoint3 237, 22, 0 LWMPoint3 253, 83, 0 LWMDataAreaFill1x1 0, _Flatten_, 1, 0, 17 LWMDataAreaHeight 5, 101 LWMDataAreaFill1x1 0, _Flatten_, 1, 1, 17 LWMDataAreaHeight 5, 101 LWMDataAreaDrawPolygons 1,_Flatten_,1,2,16 LWMPoly3 11, 0, _Water_, 5, 101, 5, 101 LWMPoint3 7, 84, 0 LWMPoint3 142, 41, 0 LWMPoint3 155, 26, 0 LWMPoint3 172, 27, 0 LWMPoint3 176, 69, 0 LWMPoint3 166, 81, 0 LWMPoint3 152, 106, 0 LWMPoint3 140, 186, 0 LWMPoint3 100, 255, 0 LWMPoint3 1, 255, 0 LWMPoint3 1, 83, 0 LWMDataAreaDrawPolygons 1,_Flatten_,1,2,17 LWMPoly3 9, 0, _Water_, 5, 101, 5, 101 LWMPoint3 72, 49, 0 LWMPoint3 59, 105, 0 LWMPoint3 55, 179, 0 LWMPoint3 70, 224, 0 LWMPoint3 43, 244, 0 LWMPoint3 30, 255, 0 LWMPoint3 1, 255, 0 LWMPoint3 1, 1, 0 LWMPoint3 100, 1, 0 LWMDataAreaDrawPolygons 1,_Flatten_,1,0,18 LWMPoly3 8, 0, _Water_, 5, 101, 5, 101 LWMPoint3 173, 155, 0 LWMPoint3 125, 153, 0 LWMPoint3 120, 160, 0 LWMPoint3 57, 157, 0 LWMPoint3 1, 161, 0 LWMPoint3 1, 1, 0 LWMPoint3 255, 1, 0 LWMPoint3 255, 186, 0 LWMDataAreaDrawPolygons 1,_Flatten_,1,1,18 LWMPoly3 6, 0, _Water_, 5, 101, 5, 101 LWMPoint3 255, 224, 0 LWMPoint3 229, 255, 0 LWMPoint3 186, 255, 0 LWMPoint3 1, 186, 0 LWMPoint3 1, 1, 0 LWMPoint3 255, 1, 0 LWMDataAreaDrawPolygons 1,_Flatten_,1,1,19 LWMPoly3 3, 0, _Water_, 5, 101, 5, 101 LWMPoint3 219, 13, 0 LWMPoint3 186, 1, 0 LWMPoint3 229, 1, 0 LWMDataAreaDrawPolygons 1,_Flatten_,1,2,18 LWMPoly3 7, 0, _Water_, 5, 101, 5, 101 LWMPoint3 20, 10, 0 LWMPoint3 17, 60, 0 LWMPoint3 28, 124, 0 LWMPoint3 46, 169, 0 LWMPoint3 1, 224, 0 LWMPoint3 1, 1, 0 LWMPoint3 30, 1, 0 LWMDataAreaDrawPolygons 1,_Flatten_,1,19,16 LWMPoly3 4, 0, _Water_, 0, 0, 0, 0 LWMPoint3 194, 80, 0 LWMPoint3 132, 1, 0 LWMPoint3 255, 1, 0 LWMPoint3 255, 152, 0 LWMDataAreaDrawPolygons 1,_Flatten_,1,20,16 LWMPoly3 12, 0, _Water_, 0, 0, 0, 0 LWMPoint3 46, 19, 0 LWMPoint3 63, 14, 0 LWMPoint3 118, 78, 0 LWMPoint3 179, 169, 0 LWMPoint3 174, 180, 0 LWMPoint3 215, 237, 0 LWMPoint3 201, 255, 0 LWMPoint3 201, 255, 0 LWMPoint3 87, 255, 0 LWMPoint3 1, 152, 0 LWMPoint3 1, 1, 0 LWMPoint3 23, 1, 0 LWMDataAreaDrawPolygons 1,_Flatten_,1,20,17 LWMPoly3 6, 0, _Water_, 0, 0, 0, 0 LWMPoint3 181, 28, 0 LWMPoint3 220, 75, 0 LWMPoint3 255, 88, 0 LWMPoint3 255, 201, 0 LWMPoint3 87, 1, 0 LWMPoint3 201, 1, 0 LWMDataAreaDrawPolygons 1,_Flatten_,1,21,17 LWMPoly3 8, 0, _Water_, 0, 0, 0, 0 LWMPoint3 1, 88, 0 LWMPoint3 5, 91, 0 LWMPoint3 26, 115, 0 LWMPoint3 25, 146, 0 LWMPoint3 60, 187, 0 LWMPoint3 27, 232, 0 LWMPoint3 1, 201, 0 LWMPoint3 1, 88, 0CELLEND_000001 label word; End of cell 627 x 192 dataI can see the part;LWMDataAreaFill1x1 0, _Flatten_, 1, 0, 17 LWMDataAreaHeight 5, 101 LWMDataAreaFill1x1 0, _Flatten_, 1, 1, 17 LWMDataAreaHeight 5, 101but as the DataAreaHeight does not have '0' for the height (which is what it is) then I am a bit stumped! Happy new year!RegardsGraeme

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