Cloudcompare is another invaluable and free tool for viewing and handling lidar data. A few things to get started:

  • When opening a .las/laz file the first question will be about loading a list of fields: just click “Apply all”. Each point can possess extra fields like color value and “scalar fields” containing classification and other technical data.

  • Next question is about shift & scale: also click “Apply all”. As coordinate values can get really big the software will by default shift them towards 0,0(,0) but it will remember this shift, so when you save it will revert to the original coordinate values.

  • These values can be permanently modified via Edit – “Edit global shift and scale”. This way the original EPSG coordinate system no longer applies and you’re working in a local coordinate system, so only do this when you no longer want to do any GIS-related operations on the data.

  • CloudCompare always has to read the complete data file and uncompress it into memory. .Copc.laz files are still handled ‘the old way’ so with large files you may quickly run out of memory.
  • Using numeric keys you can quicky switch between a number of set viewing positions.
  • Its very easy to cut a file into segments using the scissor icon (= edit > segment, or T key)
    • Draw the polyline corners by clicking, left-click to finish
    • In the small toolbar you can choose to set rectangular instead of the (default) polygonal selection
    • Click the reddish “segment in” or “segment out” button
    • Click the green ✔️ to confirm selection; the file will be split in 2 zones, containing points inside and outside the selection
  • It’s also possible to cut using an existing polyline, this has to be opened first.
  • To split out a certain points class like ground (=2): in file properties (lower left pane) you can set the active Scalar Field to classification, then Edit > Scalar Fields > Filter by value > set Range 2-2 > split. 2 new components will be created, one containing only class 2 and another containing the rest.
  • To create a terrain mesh:
    • First make sure you have an optimized file containing only ground points (and perhaps road + bridge deck)
    • Edit > Mesh > Delaunay 2.5D (XY plane)
    • Max edge length can be left 0 (=unlimited) unless your terrain isn’t rectangular, or you wish to keep holes in the mesh
    • After triangulation you can save the mesh as STL (binary) or OBJ file

The software has tons of other functions, documentation site can be found here. Real enthusiasts can use the command line or Python 😊

A more detailed but older description can be found here – many steps still apply.