Sign in to follow this  
Guest schlucke

BGL becomes stretched?!?!

Recommended Posts

Hi again all!Just wonder what I have done now,.. cant seem to backtrack any error in my mesh. here`s the case:1. Exported a file from Global Mapper, as USGS DEM, using UTM WGS84 ( and correct zone )2. Open in 3DEM, export as terrain matrix signed integer ( BIN. file)3. Used the data from the produced header file to calculate LOD cell upper left / lower right coordinates.3. Create an INF, using the NW point of my file as LAT and LON. 3 Putting in the rows and coloumns from the header file in NumofCellsPerLine=Coloumns, and NumofLines= rows. Used the LODCalc to get the cellX and CellyDIM.The file resamplse well, and i compress it, and create a BGL, BUT when i load it into my Fsim, the mesh area is a bit stretched ?. In my case its an island,.. about 40 km east west, and same nort south. but if south point is at right place, north point is 1 km to far north ??.Have double checked my data, and in DEM file coordinates are accurate,.. is this something that maybe happends when creating the BIN in 3DEM (terrain matrix signed integer) ore BIL from Global mapper itself ( - "Elevation - 2 Bytes pr sample" ) ?Tried read_dem a while ago,.. wasnt successfull,,, any ideas any1 ?.. HELP :)Freddy

Share this post


Link to post
Share on other sites
Help AVSIM continue to serve you!
Please donate today!

Hi Freddy:not entirely sure about your specific problem though it sounds like your coordinate computations might be off.I think there's a much easier way when using GlobalMapper:1. Export the file as GeoTiff, with "Always Generate Square Pixels" unchecked and "Generate TWF File" checked.2. Import the geotiff file to 3DEM (or MicroDEM) and re-save as BIN/BSQ3. Use the data from the .twf file for your .inf file, e.g. 0.00026441686504689 --> cell width in arc degrees (CellXdimensionDeg) 0.00000000000000000 0.00000000000000000 -0.00013803150092141 --> cell height in arc degrees (CellYdimensionDeg) - use as a positive number! -136.80000000000001000 --> western edge (Lon) 59.18999999999999800 --> northern edge (Lat)That should do the trick ;-)Note that the (GeoTiff) export also gives you the option to specify different export bounds, in case you want to trim the extent of your DEM.Cheers, Holger

Share this post


Link to post
Share on other sites

Hi Holger and Dick!Thx for your reply!. I have tried yesterday, using youre method. Same thing happends...Seems there are an issue with my data, as the island keeps getting to small ore big dependant on how big my DEM is. ( height especially ). It also seems my island has a slight rotation to the left. My X Y Z data are in NGO Oslo 1948 axis 7 DATUM, and it imports well into Global Mapper. When I change the projection after import to UTM WGS84, the island tilts i bit left.From you image, rhumba,,. I notice the resolution is in arc degrees. In my case it says metres behind the X and Y axis,, i use 10 metres, as this gives me a pretty good DEM file.I have now tried numorous times, but everytime i try, I cant get the island perfectly right size.. this bugs me now!..Are there any programs that I can use to import my data into and compile the mesh in ?. I loose control from the point i create the BIL, and into the BGL is created.. somewhere here I make a mistake.If any of you would like a go, I can zip togehter my X Y Z data ( 30 mb ) and send to you along with the projection file (*.prj) for Global mapper.I will provide you a more brief description when i get home tonight, with pictures in this thread..rgdFreddy Wilhelmsen

Share this post


Link to post
Share on other sites

Hi Freddy:"When I change the projection after import to UTM WGS84, the island tilts i bit left."That's your mistake right there, unless this is a typo. The projection has to be "geographic" (lat/long), not UTM! That's probably why your export screen shows meters (the unit of the UTM projection) rather than degrees. Also, the resolution of the FS mesh is determined with the LOD setting in the .inf file, and is independent of the source resolution (though you should pick a similar value). If your data are truly 10-m resolution, you could try LOD11 (19 m) or LOD10 (38m). LOD12 (9.6m) won't show in FS9 and for LOD11 you'll have to increase Terrain_Max_Vertex_Level in your fs9.cfg to see it.You probably know this but a great tool for quickly checking you mesh(including optional overlays of the default FS coastlines etc.) is Jim Keir's LWMViewer http://www.jimkeir.co.uk/FlightSim/LWMViewer.htmlCheers, Holger P.S.: I just noticed that you had mentioned "UTM WGS84" in your first post too; sorry I didn't catch it then.

Share this post


Link to post
Share on other sites

Sorry for jumping in here, but I have similar problems with my first mesh scenery and I'm also getting more and more confused. BTW: Thanks for pointing out the source data has to be LAT/LON WGS84 and not UTM. I must have missed that in the manuals, I also used UTM :(But what really confuses me are the words "LOD12 (9.6m) won't show in FS9 ...". I also have real 10m source data compiled to LOD 12 and I'm sure that I've seen the result in FS9. And as far as I know FSGenesis sells 10m meshes for FS9, so I assume it works ... !?Please help!Holger

Share this post


Link to post
Share on other sites

Hi NamensvetterSorry, I should have been more specific. You will see your LOD12 mesh but not rendered at LOD12, i.e., 9.6-m spacing. Depending on your TMVL setting it'll be rendered as either LOD10 or LOD11.See this thread: http://portal.fsgenesis.net/index.php?name...viewtopic&t=466According to Steve Greenwood - http://www.fs-traveler.com/priority.shtml - the general mesh display threshold is even lower, at LOD10, but Justin (FSG) has heard otherwise http://portal.fsgenesis.net/index.php?name...ght=mervyn+tmvlNot sure if that helps with the confusion but that's as much as I know ;-)Cheers, HolgerP.S.: I believe that the screenshot attachments in the FSG forum become visible only when you sign up (free) as a forum member.

Share this post


Link to post
Share on other sites

Hi again all!!Finally success!!... my mistake not using the gegraphical projection. Island comforms superb in LOD11, and details are stunning... Only thing left now is to edit the LWMs ... since i got no data that cover the entire H*954060.bgls seems I am stuck to wait for MS and their SDK..So far I got very many cliffs and flatlands around the coast,.. See this picture how the island is in shape compared to the default shoreline.Http://www.wilhelmsen.net/screen/enhv_mesh/bareoya.zipAny of you got any experience with the program called AutoASM ?Thx for your tremendous help !!rgdFreddy and Tor Egil.

Share this post


Link to post
Share on other sites

Hallo Auswanderer,the information was very usefull, thanks for that. Seems that I have to end up with a LOD11 for the details and a LOD9 or LOD10 for the "far away" view. As far as I understand that schould work. But it is a pitty that I can't use the 10m source data due to MS bugs in FS9. The island of Tutuila (American Samoa) has very interesting landscape and it would be worth to build it with LOD12 I think.Anyway, I think the harder part is to draw the coatlines/rivers/roads and to assign the Land/Water classes with Ground2k4! I hope that I can place everything correct according to the mesh.I've read about problems with TMVL=21, FSG Europe 76m and the german rivers from Rainer Duda (just as an example): The rivers are some meters left or right to the river bed with TMVL=21, with TMVL=19 everything is fine. Seems that I will run into lot of problems with such a small island ;) And all I thought was: lets start with a small island, that schould be easy :)HolgerPS: I've signed up at FSG, perhaps see you there.

Share this post


Link to post
Share on other sites

Hi Freddy:great to hear that you've got the mesh in place - congratulations!"Only thing left now is to edit the LWMs ... since i got no data that cover the entire H*954060.bgls seems I am stuck to wait for MS and their SDK.."Actually, you can replace the LWM and VTP water & shorelines for your island with more accurate one and remove that section from the default HP9/HL9 files. You can use Jim Keir's LWMViewer to decompile the source data, Wordpad to edit them, and the MS BGLC.exe to recompile them. That's what I did for the Glacier Bay files. You will need to be able to read the .bgs files but the structure isn't that difficult; the data are sorted by LOD8 cells and then by LOD13 areas (also, there's a header at the top of each file and the index at the bottom). Richard's (Ludowise) LWM tutorial explains the basics of the code as does the FS2002 Terrain SDK. There have been some changes in FS9 and you'd have to search in the scenery design forum to find the respective threads.Of course, publishing an edited default file can lead to confusion if different designers do this for the same LOD5 area. However, if your area is fairly remote then it shouldn't be an issue.Cheers, Holger

Share this post


Link to post
Share on other sites

Hi Freddy.You can use LWMViewer to get the source code for the HP file, then use Edgar Knobloch's LWM converter to make all the water mesh-clinging:http://library.avsim.net/esearch.php?CatID...Scen&DLID=43104Replacing the default HP*.bgl with the converted HP*.bgl allows you total freedom to make new water without the default flattens interfering. Then you could work on a smaller section without disturbing the shapes of the larger HP file.Will the default water then look odd? Yes, but it is already wrongly shaped and placed... it would now also be non-flattened... not much worse. ;)The best solution is to replace the whole HP and HL files with the right data... but beyond the patience of most designers.Dick

Share this post


Link to post
Share on other sites

Hi all!Just wanted to show off the result of my new mesh.Here is some screenshots.Original FS9 meshHttp://www.wilhelmsen.net/screen/enhv_mesh/ENHVorig1.jpgMy LOD11 meshHttp://www.wilhelmsen.net/screen/enhv_mesh/ENHVmesh1.jpgOriginal FS9 MeshHttp://www.wilhelmsen.net/screen/enhv_mesh/ENHVorig2.jpgMy LOD11 meshHttp://www.wilhelmsen.net/screen/enhv_mesh/ENHVmesh2.jpgOriginal FS9 MeshHttp://www.wilhelmsen.net/screen/enhv_mesh/ENHVorig3.jpgMy LOD11 meshHttp://www.wilhelmsen.net/screen/enhv_mesh/ENHVmesh3.jpgAs for editing the default ASM, I will give it a go,... have already managed to convert the existing HP*.bgl to cfs2 type, and have added Coastline to my island (both LWM and VTP). AutoASM is a great tool for prosessing large areas.!Will continue the work enhancing my scenery, will replace roads, streams lakes and deafult flatten area to the airport. Will notify you all when I upload this file for you all..rgdFreddy Wilhelmsen

Share this post


Link to post
Share on other sites

Hi Freddy,your result looks nice. Wish I would be at that point ...Where can I get the tool "AutoASM"? Did a google search, but didn't find a download site.Bye,Holger

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
Sign in to follow this