Using Litree in PDAL

Question

I am trying to use the filters.litree to segment individual tree. It seems it requires an HeightAboveGround field which I make sure my las file has. But despite this fact, I still get this error message: filters.litree: Missing HeightAboveGround dimension in input PointView.

My pipeline is written as is:

tree_id = """[
"test.las",
{
    "type":"filters.litree",
    "min_points":50,
    "min_height":10.0,
    "radius":200.0
},
{
    "type":"writers.las",
    "filename":"tree_id.las",
    "minor_version":1.4,
    "extra_dims":"all"
}]"""

Answer 1

When reading from a las-File, be sure to specify which dimensions should be read, by replacing the input file with a pipeline entry for readers.las:

...
{
     "type": "readers.las",
     "filename": "test.las",
     "extra_dims": "HeightAboveGround=float"
},
...

You can also try setting use_eb_vlr to true instead of specifying extra_dims manually. For more options, see the documentation: https://pdal.io/stages/readers.las.html