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Guest Pat 1

Resample problem in Terrabuilder

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Hi allI have been trying to make some mesh and have got really stuck:I cannot get resample to compile mesh in LOD grids next to those bounded to the north by N49 13.12. I can get valid resamples(meshes appear fine in f2004) everytime using overlap of 0.0005 at the grid that ends at N49 13.12 but never in the grid that starts at N49 13.13. I also get this result for every one of a dozen longitudes I have tested around the globe.Grateful for any ideas/help.Thanks

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Sorry, Pat, but I am at a loss why this particular latitude... I have encountered anomalies here and there, perhaps something to do with the imprecision of FS grid system.

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Hi MishoDo you think I could get it to work if I tried resampling with different cell dimensions/positions in the cell and or overlap figures? If not is there anything else I could try?Thanks

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I would try moving the NW corner a bit more N and W, so that origin falls outside of the LOD cell you're trying to resample - see if that works. Make sure you overlap the LOD on all of the edges...let us know if that works.

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Hi MishoIn Destination Properties I tried this on a quadrant that works using the usual method of 0.0005 overlap but no joy: First I entered figures exactly per the quadrant location but this didnt work (I guess because I hadnt allowed for the 0.0005 overlap). Then I tried adjusting the east and south points by the change equivalent to the 0.0005 overlap. I got the figures from the cell changes seen when I used the overlap figure. I added the differences to the east and south points in the destination properties box. Still nothing!I also tried this in one of the 'trouble' quadrants without any success.Misho I dont know if I have missed something obvious or if you can see any errors in my approach but I would be grateful if you could tell me if you or anyone else can get a valid resample for any of these quadrants just to give me some hope!Pat

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Are you sure you are using the overlap option correctly?More on overlap, increment and the "magic value" can be found in the GMAX Terrain tutorials. Concentrate on the "Mesh Module Topography Processing in TerraBuilder" of the http://www.terrabuilder.com/GMAX/GMAXMM_Tut.htm file.Advanced tutorial:http://www.terrabuilder.com/GMAX/GMAXMM_AdvTut.htmBasic tutorial:http://www.terrabuilder.com/GMAX/GMAXMM_Tut.htmReference:http://www.terrabuilder.com/GMAX/GMAXMM_Ref.htmLet me know if this helps or just confuses you more :)

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Hi MishoThanks - I just needed to spend a bit of time on getting the figures right and sometimes the resample seems a bit temperamental.But I now have two new problems:1) Intermittent "v" bar shaped trenches and hills(like -/+ 50 feet or so) lining up north/south. They seem to appear a little to the right of the quadrants and run the whole way along the mesh from north to south.2) Along some of the east/west quadrant borders (ie running north-south) the mesh dips down to zero height and then back up to give very deep "v" shaped trenches running all the way along the quadrants.Thanks:)

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>Thanks - I just needed to spend a bit of time on getting the>figures right and sometimes the resample seems a bit>temperamental.Yes - "resample.exe" is extremely temperamental. The whole overlap/incremet business is the proof of that - I spent weeks tweaking it. At this point, it is more of an art than science to get it just right. I frankly thought more people would be asking questions like yours, and now I know why: It is just too complicated ;)>>But I now have two new problems:>1) Intermittent "v" bar shaped trenches and hills(like -/+ 50>feet or so) lining up north/south. They seem to appear a>little to the right of the quadrants and run the whole way>along the mesh from north to south.>>2) Along some of the east/west quadrant borders (ie running>north-south) the mesh dips down to zero height and then back>up to give very deep "v" shaped trenches running all the way>along the quadrants.>One advice: carefully check your data. Everything, from extents to sizes of samples. TMFviewer is a great app to see what exactly is going on without actually going to FS...

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"One advice: carefully check your data. Everything, from extents to sizes of samples. TMFviewer is a great app to see what exactly is going on without actually going to FS..."Ok after looking (very closely!) at TMF viewer I see some of the meshes produced are bordered on one side by a narrow column of zero elevation height. The bitmaps I created are not bordered like this so I thought that the bitmaps are not stretched enough to reach the other side - but altering the overlap figures for this side does not seem to fix it - either the file won't resample at all or I get a tmf/bgl file that is twice the size and the new half being zero height. Is there a more direct way to stretch the bitmap across the quadrant?Next I thought I'd try merging two files to see if this might lose the gap I mentioned in my previous message - but when I try merging tmf files I just end up with the same file I started with. How do you merge the files?Any ideas on how to continue down this road, or new approaches recieved with thanks!I cant help thinking it must be possible to finish this - I have searched the Terrabuilder/mesh forums and not seen anything like this mentioned.

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