Global Mapper v25.0

Creating DEM for a .xyz export triangulates outside DEM bounds

AWood
AWood Global Mapper User
edited May 2015 in Technical Support
It might be just procedural but here is what I'm trying to do and what I see happening.
I have a .bil file that I need to transform from LatLong in vertical meters to a State Plane in vertical feet and then export as a .xyz
I open the .bil, then in Configuration set the new coordsys.
This doesn't change the vertical from meters to feet. The procedure I was told to fix this was to create point features, then create a new elevation model in feet, then create point features on that to export.
The elevation model triangulates across the empty data areas. Then, when creating point features again, it creates thousands (100s of thousands :-) of unneeded points and therefore bloats the resulting .xyz export.
Is there a better way to approach this?
Here is a video of what I'm doing http://screencast.com/t/X9vd7bXwMg
Let me know if I can provide more info.
Thanks in advance for any help.
Best regards,
AWood

Comments

  • global_mapper
    global_mapper Administrator
    edited May 2012
    There is a much better way to do this! You are correct to change the projection on the Projection tab of the Configuration dialog to the new coordinate system. This controls the horizontal units. The vertical/elevation units are actually set as an option when you do the XYZ Grid export using File->Export Elevation Data. There is an option on that dialog to choose the output elevation units. Just set them to feet there and the meters from the original BIL file will be converted to meters.

    Let me know if I can be of further assistance.

    Thanks,

    Mike
    Global Mapper Guru
    gmsupport@bluemarblegeo.com
    http://www.globalmapper.com
  • AWood
    AWood Global Mapper User
    edited May 2012
    Hey Mike,
    Thanks for the quick reply.
    I did the straight export - your procedure created a significantly smaller, more manageable file...
    I sent it off to the client for them to test and I'll post back if it works.
    Thanks again,
    AWood
  • Yolandie
    Yolandie Global Mapper User
    edited June 2012
    Hi,

    I want to find out how to create an DEM file to use it in the Viewshed. I got my files from Modelmaker, which exports it into an Ascii file(txt), yxz file and an DXF file.
    I saw that i can convert it into a DEM file in Global mapper from a yxz file, but then it goes all funny.

    Can you please help with this
  • global_mapper
    global_mapper Administrator
    edited June 2012
    How exactly does it go all funny? Are there areas of terrain created far from your sample points that you don't want? If so, use the grid tightness slider to make sure you only create terrain near the actual sample points to avoid the large smeared areas that are inside the convex hull but not near areas of known elevation.

    Thanks,

    Mike
    Global Mapper Guru
    gmsupport@bluemarblegeo.com
    http://www.globalmapper.com
  • magheralex
    magheralex Global Mapper User
    edited May 2015
    How exactly does it go all funny? Are there areas of terrain created far from your sample points that you don't want? If so, use the grid tightness slider to make sure you only create terrain near the actual sample points to avoid the large smeared areas that are inside the convex hull but not near areas of known elevation.

    Thanks,

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

    Hello,
    Would you like to help me with this error occured while trying to generate a grid from a big xyz file ?

    "Unable to grid 3D points from selected overlays.
    TriangulatedSurface.cpp - 606
    Version: v14.0.0 (64-bit)
    Build Time: Sep 12 2012 11:13:31"

    Thank you in advance.