Using Laspy to Create LAS Files from Scratch

Question

I have found instructions for creating a las file by opening an existing file, modifying it, then re-saving it.

This re-uses the headers from the original file.

But how do I create a new file from scratch without loading another in the first place? I cannot see any documentation on the required format for the file, points, or headers.

I only need the bare minimum: x,y,z position for each point.

Here is how I assumed it might work…

import numpy as np
import laspy
import laspy.header
import laspy.file

points = []

#x,y,z values
points.append([0,0,10])
points.append([1,0,10])
points.append([2,0,11])

header = laspy.header.Header()
outFile = laspy.file.File("./output.las", mode = "w", header = header)
outFile.points = np.array(points)
outFile.close()

This fails with:

-> outFile.points = np.array(points)

/laspy/file.py
-> self._writer.set_points(new_points)

laspy/base.py
-> self.data_provider._pmap[:] = points[:]

ValueError: could not broadcast input array from shape (3,3) into shape (3)

Could anyone kindly point to some sample code or tips to get this working?

Answer 1

Rather than setting the entire points array in one go, try setting each dimension in turn:

import laspy

header = laspy.header.Header()
outfile = laspy.file.File("output.las", mode="w", header=header)
outfile.X = [1, 2, 3]
outfile.Y = [0, 0, 0]
outfile.Z = [10, 10, 11]
outfile.close()