Global Mapper v25.0

Updating elevations

geo72
geo72 Global Mapper UserTrusted User
edited January 2014 in Bug Report
Hello Mike,

I discoverd a "problem" when updating elevations for features, which are partly not within the elevationlayer and have a suggestion solving this:

1) Allow updating the elevations for the vertices that are above the elevationslayer and

2) For the vertices, where no elevationlayer exists, let the user decide:
a) delete vertices
b) keep existing elevations
c) Interpolate the elevations

At the moment the user has to delete the vertices (that have no elevationlayer) manually, which can be quite timeconsuming.
What do you think?

Please find the screenshot attached for illustration.

Thanks!

Oliver

unable_to_update_elevations.png

Comments

  • global_mapper
    global_mapper Administrator
    edited January 2014
    Oliver,

    What you could do now is export your terrain layer with gaps to a new elevation file and check the box to 'Fill Small Gaps'. This will interpolate in the gaps to get a filled surface. You could then use that to assign elevations to the features without having any problems with no-data areas. Another option would be to first load some background data to fill in the holes.

    Thanks,

    Mike
    Global Mapper Guru
    geohelp@bluemarblegeo.com
    Blue Marble Geographics for Coordinate Conversion, Image Reprojection and Vector Translation
  • geo72
    geo72 Global Mapper User Trusted User
    edited January 2014
    Hello Mike,

    Thanks for your suggestion (fill small gaps first and assign elevations afterwards). Of course that works, but I have a different intention. I want to create the most accurate terrainlayer possibe using 3D-breaklines and an exact orthophoto with the following workflow:


    1) Draw 2D-breaklines using the orthophoto (for example edges of a streeet)

    2) Densify the 2D-breaklines to have more vertices

    3) Assign elevations to the breaklines (of step 1) using the raw terrainlayer (with gaps) to get 3D-breaklines

    4) Calculate a new (more accurate and filled) terrainlayer using (a) the raw terrainlayer and (b) the 3D-breaklines form step (3).


    My suggestion to allow always updating elevations for features (also if there are some vertices without a terrainlayer) is beacause of step (3). As I mentioned in my original post - the other vertices, which do not have an elevationlayer could be deleted for example.


    Do you know what I mean?

    Thanks,

    Oliver
  • geo72
    geo72 Global Mapper User Trusted User
    edited January 2014
    just to mention: getting perfect breakline-elevations is also associated with the item#12612: http://www.globalmapperforum.com/forums/suggestion-box/10874-editing-3d-lines-line-best-fit.html

    I am really looking forward to this:)

    Thanks!

    Oliver
  • geo72
    geo72 Global Mapper User Trusted User
    edited January 2014
    for info to all: my solution for getting the elevations for the 2D-breaklines at the moment is the following:

    1) build an area-feature where no elevation-layer exists
    2) while showing all vertices "select all line features within the selected areas" from the "advanced sel. dialog" (see also http://www.globalmapperforum.com/forums/technical-support/11048-selection-vertices-inside-outside-area.html)
    3) delete the selected vertices
    4) now working: assign the the elevations to the line-vertices with the elevation layer

    @Mike: Thanks!

    Oliver