Global Mapper v25.0

Scaling DEM to enhance topography

cbroger
cbroger Global Mapper User
edited September 2012 in Technical Support
I have DEM for South America and would like to re-scale over one exploration block and enhance the topography. I thought I was able to easily do this in Version 11, but now in version 13 it is not working as I remember. I am going into the Overlay Control Centre – Selecting the DEM layer – Options – Alter Elevations Values and editing the range to suit the elevations over the block. Before – my DEM would re-scale and the full colour range would be reflected the new limits, but now the colour range is just clipping to the min/max value. Any help would be greatly appreciated. – Thanks Carole

Comments

  • tjhb
    tjhb Global Mapper User Trusted User
    edited September 2012
    I suggest you use the upper part of the Alter Elevation Values dialog, particularly the Scale Factor and Offset boxes (but the Power box is useful too, if you want non-linear scaling). Without knowing the elevation range in your dataset it's hard to say more than that, except that these boxes will allow you to rescale however you like.

    The lower boxes are not for rescaling/offsetting, but for filtering existing elevations (with the option of clamping or clipping, as you are seeing).
  • global_mapper
    global_mapper Administrator
    edited September 2012
    Also what elevation shader are you using? Some are configured to scale to the loaded elevation range, but others, like the Global Shader, have fixed colors for particular elevations so the display doesn't change as you modify the loaded valid range.

    Thanks,

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