Selecting LAS Points by Polygon

mprentermprenter Global Mapper UserPosts: 24Trusted User
Hi, I've got a few LAS files where I would like to draw a shape around the water and classify it as water.  From what I've see, I can use the Digitizer tool to select the lidar points, but it seems to always draw a rectangle.  Ideally, I'd like to select the points by digitizing a polygon.  Is there a way to select LAS points either by digitizing points on the fly or by importing a shapefile containing polygons and telling the software to select all points that fall within the polygons?  Then I could just hit the water classification button.

PS - I'd prefer not to use the profile/path tool as these points are all RGB encoded so I can easily see water from the top view.


Best Answer

  • bmg_bobbmg_bob Global Mapper Programmer Posts: 2,188
    Answer ✓
    You need to have the Digitizer turned on to select the polygon(s) using the mouse (sorry...left that detail out), or you can use the Control Center to select all of the areas in a layer at once (select the layer, right-click, and choose Select All Features in Selected Layer(s) using the Digitizer Tool.


  • bmg_bobbmg_bob Global Mapper Programmer Posts: 2,188
    To select points within a polygon:
    1) Draw a polygon using the Digitizer (or load it from a shapefile or other vector file.)
    2) Select the polygon(s)
    3) Right-click and choose Advanced Selection Options->Select All Point Features Within the Selected Area(s)
  • mprentermprenter Global Mapper User Posts: 24Trusted User this new to version 17?  I'm running 16.2.  When I select a polygon, the "Feature Information" window comes up.  Right-clicking doesn't do anything but refresh the Feature Information window.  ???
  • mprentermprenter Global Mapper User Posts: 24Trusted User
    Thanks!!!  That works great.

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