Exporting as DXF Elevation Grid with Same Options Used in AccuTrans 3D

BrianZ111BrianZ111 Global Mapper UserPosts: 42Trusted User
edited July 2014 in Elevation Data
Last question about DXF, I promise! :D After I load a DXF or LiDAR file, rectify if DXF, and grid it, I need to export the gridded layer out as a DXF with specific options for the software I'm using. Right now I'm using AccuTrans 3D to save the DXF with these options:

accutrans_save.jpgdxf_tab.jpg

I'm wondering if it is possible to just export out of Global Mapper with these options. In Global Mapper there are 3 different DXF choices: DXF 3D Face/TIN File, DXF Mesh, and DXF Point File. I've tried them all with different options but nothing seems to work when I try to load the output in the software I'm using. Here is an example of the output from AccuTrans 3D that works in the software I'm using: http://www.zagerdesign.com/temp/becc_dxf_output.zip. What options do I need to use in Global Mapper, or is it not possible?

If it's not possible, what is the best format to export out of Global Mapper for loading into AccuTrans 3D? Right now I'm using Arc ASCII Grid and this seems to work but I'm not very familiar with these formats so any guidance is appreciated. I know saving between different formats can degrade quality so what's best for avoiding this?

Thanks.

Comments

  • global_mapperglobal_mapper Administrator Posts: 17,238
    edited June 2014
    The DXF 3D Face option from Global Mapper should use the same entity types as the sample that you provided. Does your other software perhaps require coordinates in some small range so you have to offset/scale them, or perhaps set them up in a projection that generates coordinates in a particular range?

    I did notice your sample had XY values between around -1000 to 1000 and a much smaller range of Z values. I also noticed the DXF sample didn't have a header section but jumped right in to TABLES and ENTITIES in the DXF header. This is fine, but GM will add a header and many other fields at the start of the DXF. This shouldn't matter as software should just ignore any parts that it doesn't understand, but sometimes other software has strange restrictions on what it is able to read.

    Thanks,

    Mike
    Global Mapper Guru
    geohelp@bluemarblegeo.com
    Blue Marble Geographics for Coordinate Conversion, Image Reprojection and Vector Translation
  • BrianZ111BrianZ111 Global Mapper User Posts: 42Trusted User
    edited June 2014
    Yeah the Max for the X and Y coordinates is 2048 and the Min is -2048. If part of it lies outside of that area it will still load anything inside of that. If all of it lies outside of that I basically won't see anything. To make sure I don't lose anything I use the centering option in AccuTrans 3D. There is plenty of extra area around it in this case but sometimes I do use the whole area and therefore need an accurate centering. The Z values get centered by AccuTrans 3D too although I don't know if it matters there. It may also be a -2048 to 2048 but I've never tested this. The whole thing is in meters and land elevations don't get that extreme in that small of an area, at least not in my use case. Although, if they started at an elevation outside its limits it may be a problem.

    As far as headers, I have no idea but it wouldn't entirely surprise me if it messed it up. It seems like the software is a little finicky about the format. I only know the options to pick in AccuTrans 3D from someone who has contact with the developer.

    Thanks for pointing me in the direction of the 3D face option. I will play around with it more.
  • BrianZ111BrianZ111 Global Mapper User Posts: 42Trusted User
    edited June 2014
    So I tired 3D Face again with default settings and the software doesn't even show a mesh to import when I load it. The only setting in Global Mapper I saw that might make a difference (because I didn't know what it did) was Export ECEF Coordinates. I tried checking that and now the software shows a mesh called DefaultLayer but nothing shows up when I import it. Possibly everything is outside the -2048 to 2048 range?
  • BrianZ111BrianZ111 Global Mapper User Posts: 42Trusted User
    edited June 2014
    I found an option in AccuTrans 3D to save with headers: "Output Header, Tables, Blocks and Entities". It works so does this eliminate the headers as the cause of the problem? Here's the file: http://www.zagerdesign.com/temp/becc_dxf_output_with_headers.zip (Note: I saved at a lower resolution this time to save time in testing this)
  • global_mapperglobal_mapper Administrator Posts: 17,238
    edited June 2014
    You definitely wouldn't want the Export ECEF option, that converts the coordinates to earth-centered earth-fixed which are 3D coordinates relative to the center of the earth. Almost nothing will handle those.

    It does sound like the header isn't the issue, although there could be some particular line of the file AccuTrans 3D doesn't like. Can you provide them with a sample exported from GM as 3D Faces and see if they can pinpoint the issue? It wouldn't really be practical to work backwards from something that works in their software, it's much easier if they can just say what they don't like and hopefully even update their software to handle a wider variety of DXF files.

    Thanks,

    Mike
    Global Mapper Guru
    geohelp@bluemarblegeo.com
    Blue Marble Geographics for Coordinate Conversion, Image Reprojection and Vector Translation
  • BrianZ111BrianZ111 Global Mapper User Posts: 42Trusted User
    edited July 2014
    The developer of the software I use isn't supporting it anymore as they are creating a new 3D engine now. Looks like I'll just stick to my current process for now then:

    LiDAR or DXF > Global Mapper > Arc ASCII Grid > AccuTrans 3D > DXF > 3D engine software.

    Unless somebody has a suggestion for a better format then Arc ASCII Grid to go between Global Mapper and AccuTrans 3D. Thanks anyway for the help though.
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