Rhumbaflappy. Would you help me with BIL's

[Guest Richard Hill]

I am running Windows XP ans something is wrong! I made a folder, copopied all data, INF, BAT Resample, TMF2BGL, Tmfcompress. run the BAT file get a flash of activity but nothing is ever created. Would you do a test for me on Clarksburg_ 80.0 - W 79.0 W 40.0 N 39.0 N and send me the list of files you placed in the folder, the BAT and INI file, so I can find out what I am doind wrong? Steve suggested I go to the DOS prompt but XP has no DOS prompt.I have downloaded all my data now I want to create my mesh, but sio far no sucess.Richard;

[rhumbaflappy 113]

Hi Richard.I think you do need the DOS screen. It's in 'C:WINDOWSsystem32' and is named "cmd.exe"Just copy "cmd.exe" to the same folder with the rest of the items, and double-click it. It will bring up a DOS command window, and then Steve's batch file should work ( and you will be able to see the error message, if something is wrong ).I always use this dos command window with resample, whether making mesh, landclass or CUSTOM.==============Are you using the NED data from the USGS seamless website? Attached with the BIL file should be a metadata file, and within it you are given the exact extents of the data, and the celldimension numbers... in case you want to check.Dick

[rhumbaflappy 113]

Hi Richard.Try this approach:http://www.flatface.net/~rhumba/Zips/N40W80Mesh.zipThis contains what you'll need to make the mesh at LOD 9 for one degree with the NW corner at N40 W80.You'll need to download the NED data ( as BIL format ) for this area:N = n40.2W = w80.2S = n38.8E = w78.8Get it from:http://seamless.usgs.gov/You need the "overhang" to insure the whole 1 degree area gets meshed.Dick

[Guest Richard Hill]

Dick;According to your readme you downloaded a 2X2 degree BIL, all of mine are 1X1 degree. From the HDR file do I use NROWS/NCOLS or BANDROWBYTES/TOTOLROWBYTES? Why I am asking I used yourinf and am not sure things would be right although it created the BGL.Again thanks;Richard L Hill

[rhumbaflappy 113]

Hi Richard.N = n40.2W = w80.2S = n38.8E = w78.8That's 1.4 degrees each way. A 20% overhang in each direction to insure the entire 1x1 degree area would get meshed. Resample will have no problem with this, and the download is free, so we can be generous. You can't get 1x1 degree exactly with the mesh, as it must be a multiple of the world LOD9 division. Excess data is a good thing for mesh, CUSTOM, or landclass data, as long as the INF is exact. The resultant BGL will be slightly larger than 1x1 degree. This shouldn't be a problem in the sim.Here's the HDR file contents:BYTEORDER ILAYOUT BILNROWS 5040NCOLS 5040NBANDS 1NBITS 16BANDROWBYTES 10080TOTALROWBYTES 10080BANDGAPBYTES 05040 is what we want, because each elevation is 2 bytes of data ( Note the NBITS is 16, not 8 ).If a bgl is made of the data I specified, it can be checked with TMFViewer for the extents. The BGL I made was accurate, and covered the whole 1x1 degree area, and a little excess, as I explained.Once you get the hang of it, you can experiment with multiple source INFs, or multiple INF resamples, or using TMFMerge to merge the uncompressed TMFs into a larger BGL.All that being said, there already is a good US mesh set at Simviation for free download. And lots of simmers already have mesh that they like. So including US mesh in a scenery package might be a bit of overkill... at least until the corrected SRTM data is available in a year or two.But at least your getting an education on resampling mesh. :)Dick

[Guest Richard Hill]

Dick;OH well, sgreenwood told me to download 1 degree BIL files, even attached HTML examples. I spent 5 days downloading the files. I have to go through sugery soon, so maby I will give it a try again magy not. I guess I can live with all the errors.Thanks for your help;Richard L Hill

[Guest sgreenwood]

Sorry for the misunderstanding, Richard. That was intended as an example of how to download ANY bil data, not a specific recommendation regarding file size. Almost any sizes will work, as long as they are chosen carefully. Working style, PC capabilities, download speed and many other factors become important when working with this much data. There is quite a bit of information about matching source data to LOD in the "Tips" section of my website. I also have an LOD calculator (Excel 2000) available, which will help you understand LOD issues better. It is a useful starting point to which you can add your own task-specific worksheets, for example to calculate the optimal file sizes to order, depending on LOD. The new "Enhanced" Seamless Data Server now extracts only data that lies inside the requested coordinates, so I'm afraid you may have problems with the files you have downloaded (gaps in the mesh along the borders).I strongly recommend a modest initial approach to any new undertaking. Develop some proficiency with the material and establish efficient work habits before moving on. The larger the task, the greater the payoff for such a "pilot project".Hope the surgery goes well.Stevewww.fs-traveler.com

[rhumbaflappy 113]

Hi all.Resample requires the source area to be equal to or larger than, the destination.Your destination area must be a multiple of the LOD level yor are using. LOD5 for landclass and CUSTOM.. mesh can generally be LOD6-LOD11. Mesh can be less than LOD6, but it may not show in the sim. Mesh can be reater than 11, but the FS2002.cfg file needs alteration to show this.If your requirements are, for example, 1 degree by one degree, then your destination area must totally enclose that requirement.http://forums.avsim.com/user_files/22684.jpgIn the above picture, the design requirement is smaller than the Destination Area ( the actual mesh ). This overlap is needed to insure the whole requirement gets meshed... and the source overlap is needed to insure the destination area is right.The sim does a good job of sorting out overlapping destinations ( meshes ) even if they are the same LOD.So a project could have several overlapping meshes of the same LOD level, and it will be fine in the sim, and look rather seamless.Dick

[Guest]

Great picture, does a good job explaining things.Tim

[Guest sgreenwood]

Hi Dick,Here is an image I downloaded from a forum quite a long time ago. It is an excellent graphic which identifies the essential aspects of the LOD grid system. The only error is the calculation of the position of the SE corner, which we now know should have 1 subtracted from the number of rows and columns. Unfortunately, the associated text has been separated from the image so I can't give proper credit to the author.http://forums.avsim.com/user_files/24649.jpgAnd speaking of acknowledgements, a belated thanks for all your kind words of late. They are much appreciated!Steve

[rhumbaflappy 113]

Hi Steve.It is a good illustration. Maybe the author will step forward and take credit.Any kind words from me, or anyone else, are very much deserved when they are spoken of you. You have given a great help to the mesh design community, and your website is top notch.Your payware mesh is of the highest quality and sold with a great deal of honesty... something that is sometimes "clouded" with other payware meshes. People buying your products will know what they are getting.Shameless plug for Steve Greenwood:http://fs-traveler.com/products.html:)Dick