Global Mapper v25.0

Create polygons with elevation relative to Ground Level

I have different type of 3D areas (polygons) :
- elevation data of some areas are mentionned above Sea Level
- others are mentionned above Ground Level (relative to DEM)
- and others again are a mix of both.
I know it is possible to create point/areas with altitude data (above sea level) using attributes ELEVATION (for altitude info) and 3D_EX_HT (for thickness/height of the area). There's no problem for these.
But how can I do with the second or the third type of areas? For example, I have an air zone which goes from 5000ft to 10000 ft above Ground Level or an air zone which goes from 5000ft above Ground Level and which goes to 30000ft above Sea Level.
How can I create them using SDK (GM_VectorFeature_t,...)?

Thank you for your help

Answers

  • aaronc
    aaronc Trusted User
    edited May 2016 Answer ✓
    There is no way to do that with Global Mapper.  You will need to first convert all elevation data to the same type.  You could easily convert the data using Geographic Calculator.

    Hopefully that helps.
  • Thank you very much Aaron!

    By using Geographic Calculator, do you mean searching the layer which represents the DEM and using the GM_GetLocationElevation function or are there others automatic functions ?
  • aaronc
    aaronc Trusted User
    Answer ✓
    What I mean is you need to have all of the elevation in the same format before you can use the SDK functions.  Geographic Calculator is another Application that specifically does conversions and re-projections.
  • Ok!
    Thank you again Aaron