Importing a terrain mesh into GM?

tim53tim53 Global Mapper UserPosts: 68Trusted User
edited April 2015 in Elevation Data
How can I import a terrain mesh into Global Mapper? What format do I need to export an existing terrain mesh to a DEM so that GM can read it?

-Tim.

Comments

  • global_mapperglobal_mapper Administrator Posts: 17,238
    edited December 2012
    Tim,

    Generally a terrain mesh might be in a DXF mesh/3D face file, or a 3D area Shapefile. Really any 3D area format would work though.

    Thanks,

    Mike
    Global Mapper Guru
    gmsupport@bluemarblegeo.com
    http://www.globalmapper.com
  • tim53tim53 Global Mapper User Posts: 68Trusted User
    edited December 2012
    So far I've been unable to save a terrain mesh with textures into a format that Global Mapper will read. I'm using Photoshop CS6 Extended and Meshlab, though I have only just started with Photoshop and haven't figured out how to export a file or what formats Global Mapper can read.
    -
    Tim.
  • tim53tim53 Global Mapper User Posts: 68Trusted User
    edited December 2012
    Forgot to add: The files I'm importing into Photoshop and Meshlab are .obj files of Mars, from the rover stereo camera data modeled into meshes and converted from Inventor .iv format.

    -Tim.
  • global_mapperglobal_mapper Administrator Posts: 17,238
    edited December 2012
    Tim,

    What formats can those applications export to? Can they make DXF, Shapefile, plain text, STL, DGN, or KML/KMZ?

    Thanks,

    Mike
    Global Mapper Guru
    gmsupport@bluemarblegeo.com
    http://www.globalmapper.com
  • tim53tim53 Global Mapper User Posts: 68Trusted User
    edited December 2012
    Tim,

    What formats can those applications export to? Can they make DXF, Shapefile, plain text, STL, DGN, or KML/KMZ?

    Thanks,

    Mike
    Global Mapper Guru
    gmsupport@bluemarblegeo.com
    http://www.globalmapper.com


    Photoshop CS6 extended can export Collada DAE, Flash 3d, Google Earth 4 KMZ, U3D, and Wavefront OBJ.

    Meshlab can export in the following formats:Meshlab_export_formats.jpg

    I've opened KMZ and DXF versions in global mapper, but after appearing to load files, I get an error saying that there's no data in the KMZ. The DXF file opens, but appears empty.

    -Tim.
  • global_mapperglobal_mapper Administrator Posts: 17,238
    edited December 2012
    Tim,

    Can you provide one of those DXF and/or KMZ files so I can see why it won't load? Another one you might try is the XYZ Point Cloud or the Javascript JSON.

    Thanks,

    Mike
    Global Mapper Guru
    gmsupport@bluemarblegeo.com
    http://www.globalmapper.com
  • tim53tim53 Global Mapper User Posts: 68Trusted User
    edited December 2012
    Hi Mike:

    Here's a line out of a CSV file we just tried:

    -1.050E+02 5.567E+01 -1.229E+00 197 154 88


    where the xyz values are in meters and the final 3 numbers are RGB values. I don't think I can send the DXF or KMZ files because they'd be huge and they're current Curiosity data, not for distribution.

    -Tim.
  • tim53tim53 Global Mapper User Posts: 68Trusted User
    edited December 2012
    I don't think I'd tried the Collada dae file before. It appears to have choked GM, as it's still trying to open after about 10 minutes.
  • global_mapperglobal_mapper Administrator Posts: 17,238
    edited December 2012
    The CSV ought to load using the File->Open Generic ASCII Text File menu command. You can grid it or bring it in as points.

    How large is the Collada DAE file? Some DAE files will load, but most have stuff that isn't supported by GM. They should all eventually finish though.

    Thanks,

    Mike
    Global Mapper Guru
    gmsupport@bluemarblegeo.com
    http://www.globalmapper.com
  • tim53tim53 Global Mapper User Posts: 68Trusted User
    edited December 2012
    Hi Mike:

    The Collada DAE file is 17MB. I'll try loading it again.

    -Tim.
  • tim53tim53 Global Mapper User Posts: 68Trusted User
    edited December 2012
    Got a "no data could be loaded from the file" after about 30 minutes.

    -Tim.
  • global_mapperglobal_mapper Administrator Posts: 17,238
    edited December 2012
    Tim,

    I am surprised it took that long for just 17MB, but not surprised nothing loaded as only a tiny subset of DAE data types is supported. How large is the file if you zip it up? If it's small enough can you post it here? I might be able to add support or at least see why it's so slow.

    Thanks,

    Mike
    Global Mapper Guru
    gmsupport@bluemarblegeo.com
    http://www.globalmapper.com
  • tim53tim53 Global Mapper User Posts: 68Trusted User
    edited December 2012
    Tim,

    I am surprised it took that long for just 17MB, but not surprised nothing loaded as only a tiny subset of DAE data types is supported. How large is the file if you zip it up? If it's small enough can you post it here? I might be able to add support or at least see why it's so slow.

    Thanks,

    Mike
    Global Mapper Guru
    gmsupport@bluemarblegeo.com
    http://www.globalmapper.com

    Hi Mike:

    I'm not going to be able to post recent Curiosity data, but we might be able to post data from Opportunity. We're trying exports into other formats first, though, since I need orthorectified mosaics on DTMs first, and terrain meshes second (which are being produced as standart products already, I just haven't been able to read them before).

    More later, and thanks!
    -Tim.
  • tim53tim53 Global Mapper User Posts: 68Trusted User
    edited December 2012
    Okay, I've been able to import a .csv file of xyz data into global mapper and export a gridded 32-bit DEM from this file.

    The file has an ID column before the xyz that's easy to skip in the dialog window in GM for importing ascii files. But so far, to open the xyi data from the ascii file, I don't know if there's a way to skip the ID,x,y,z columns to get the intensity from the I column, so we created a second csv file where we delete the z column so global mapper will get the intensity value from the intensity column. Presumably, for color texture maps (images), I'll have to do this for each of the rgb channels as well?

    Or is there another way of reading the xyi or xyrgb values from a csv file?

    -Tim.
  • global_mapperglobal_mapper Administrator Posts: 17,238
    edited December 2012
    Tim,

    If you stick a row with the names at the top of the file, like below, you can load it with the attribute names coming from the first row, then export to a Lidar LAS file to have the INTENSITY attribute stored as the point intensity. The same works for RGB if you name the columns RED, GREEN, and BLUE.

    X,Y,Z,INTENSITY
    1000,2000,345.5,65
    ...

    Thanks,

    Mike
    Global Mapper Guru
    gmsupport@bluemarblegeo.com
    http://www.globalmapper.com
  • tim53tim53 Global Mapper User Posts: 68Trusted User
    edited January 2013
    Hi Mike:

    Yesterday I downloaded version 14.1. I've tried several times to import ascii files with x,y,z,intensity (using lower and upper case versions in the first row), and I always get a point cloud of the elevation data without the intensity. Also, I can't figure out how to convert the point cloud to a gridded elevation map.

    -Tim.
  • global_mapperglobal_mapper Administrator Posts: 17,238
    edited January 2013
    Tim,

    Did you check the option to include attributes from coordinate lines? You also need to check that to get the intensity values to load. I just tested with a .xyzi file and that loaded fine as a point cloud. Also make sure if you add the attribute names that your I field is named INTENSITY. Or really just uncheck the option that the labels are in the first row.

    I think I will also add a new option to export to XYZI files.

    Thanks,

    Mike
    Global Mapper Guru
    gmsupport@bluemarblegeo.com
    http://www.bluemarblegeo.com/
  • tim53tim53 Global Mapper User Posts: 68Trusted User
    edited March 2014
    Well, I'm back!

    I still haven't been able to make this process work. I've been able to open the .csv files as point data using the ascii import dialog window and checking the "include attributes...", "Column headers in first row..." and "Treat 3rd coordinate value as elevation" check boxes. Then I used the "Export Vector Format" option with the "Save Color Value..." box checked to export a Lidar LAS file. But I still only get the xyz values displayed with a color ramp for the elevation values, not the grayscale values of the points.

    The file has this format when viewed with a text editor:

    x,y,z,INTENSITY
    -77.157303,86.480835,5.054045,67
    -78.03009,84.131081,5.152064,59
    -78.058533,84.110931,5.155144,56
    -77.799988,83.408203,5.125075,54
    -77.066597,87.274353,5.083062,63
    -76.983322,86.945702,5.071164,62
    -77.170197,87.341103,5.094424,65
    -77.319511,87.634583,5.112906,64
    -77.047066,86.598671,5.078717,64
    -76.790741,85.818657,5.04703,65
    -77.277313,87.001465,5.105613,66
    -77.315681,86.999641,5.109969,61
    -77.249626,86.723961,5.102574,60
    -76.680756,85.13179,5.035191,63
    -76.717743,85.130219,5.039392,64
    -76.671883,84.814789,5.032899,63
    -76.708595,84.813156,5.037069,65
    -77.131859,85.813972,5.087117,65
    -77.904495,83.918373,5.173006,57
    -77.759666,83.484985,5.156236,56
    -77.5644,82.932365,5.131121,57

    Like I said, I can get a point cloud that looks right (elevations look right), but it's got the color ramp displayed for the z data, not the grayscale values of the INTENSITY data.

    TIA
    -Tim.
  • global_mapperglobal_mapper Administrator Posts: 17,238
    edited March 2014
    Tim,

    If you load the XYZI file as a point cloud, then select to color Lidar by intensity you should see the points colored by the grayscale intensity value. However a direct export of that to a LAS with colors enabled won't actually save any colors as there are no raster layers to get color from and no pre-existing colors for the points. The LAS option to save with color won't get the rendered color from the points and store that, there has to be raster layers or per-existing per-point RGB values.

    So if you want intensity colors, you need to first save the intensity-colored point cloud to a raster file, like a GeoTIFF, then import that back in and do the LAS export with colors included, then the colors will pull from that raster file.

    Let me know if I can be of further assistance.

    Thanks,

    Mike
    Global Mapper Guru
    geohelp@bluemarblegeo.com
    Blue Marble Geographics for Coordinate Conversion, Image Reprojection and Vector Translation
  • JeffH@BMGJeffH@BMG Global Mapper Developer Posts: 319Trusted User
    edited March 2014
    Hi Tim,

    We've been revamping our Collada / DAE import functionality, and it's possible you would get better results with recent versions of Global Mapper. If your file is still available and it's no trouble to you, it would be interesting to know whether it would load now. If not, no big deal, but I thought that it would be worth asking.

    thanks,

    ~Jeff
  • tim53tim53 Global Mapper User Posts: 68Trusted User
    edited March 2014
    Tim,

    If you load the XYZI file as a point cloud, then select to color Lidar by intensity you should see the points colored by the grayscale intensity value. However a direct export of that to a LAS with colors enabled won't actually save any colors as there are no raster layers to get color from and no pre-existing colors for the points. The LAS option to save with color won't get the rendered color from the points and store that, there has to be raster layers or per-existing per-point RGB values.

    So if you want intensity colors, you need to first save the intensity-colored point cloud to a raster file, like a GeoTIFF, then import that back in and do the LAS export with colors included, then the colors will pull from that raster file.

    Let me know if I can be of further assistance.

    Thanks,

    Mike
    Global Mapper Guru
    geohelp@bluemarblegeo.com
    Blue Marble Geographics for Coordinate Conversion, Image Reprojection and Vector Translation

    Hi Mike:

    Is this part of the Lidar module, for which I don't have a license? Because I'm not seeing where to color the point cloud with intensity. I'm running GM version 15.1.

    -Tim.
  • tim53tim53 Global Mapper User Posts: 68Trusted User
    edited March 2014
    Oops, I see it in the control center options.
  • tim53tim53 Global Mapper User Posts: 68Trusted User
    edited April 2015
    tim53 wrote: »
    Hi Mike:

    Is this part of the Lidar module, for which I don't have a license? Because I'm not seeing where to color the point cloud with intensity. I'm running GM version 15.1.

    -Tim.

    I'm reviving this old thread because I still don't understand why I'm not able to see the point clouds with intensity. I'm having to open the point cloud first as elevation data, then make a second version of the file where I delete the "z" column and open the xyi data as another elevation layer. I can then export each layer individually as elevation grids, then render the xyi as an 8-bit raster image. Seems like a lot of steps, especially since I have thousands of these files to work with.

    This workaround works, so long as I don't set the No Data Distance Criteria to anything but "Loose". If I tighten up the distance criteria for the elevation and intensity point clouds, they don't coincide perfectly and I get a really noisy and rather ugly 3D model of the terrain.

    So, is there something I'm doing wrong that I've never been able to get the "Use colors if present (Elevations otherwise)" to work? Or does this only work with the Lidar module installed?

    -Tim.
  • tim53tim53 Global Mapper User Posts: 68Trusted User
    edited April 2015
    I'm currently using GM 16.1
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