Basic Information

  • Inspection of file contents

  • Location determination

  • Investigate suitability

Printing a Single Point

Purpose:
  • Verify PDAL is working correctly

  • Learn about point cloud data types

  • Familiarize yourself with terminal

Start Terminal (first point)

  1. Start the Conda Shell and activate the conda environment

_images/terminal.png

Command (first point)

In your Conda Shell, issue the following:

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pdal info ./exercises/info/interesting.las -p 0
  1. pdal: Run the pdal command

  2. info: info is a “kernel” in PDAL-speak. It is a unit of functionality driven by the command line.

Command (first point)

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pdal info ./exercises/info/interesting.las -p 0
  1. ./exercises/info/interesting.las: File to run info command on

  2. -p: argument corresponds to “print a point”.

  3. 0 means to print the first (starting from 0)

Run (first point)

_images/info-interesting-single-point.png

JSON output of the first point

Printing File Metadata

Purpose:
  • Investigate files

  • Verify data validity

  • Compute bounding box

  • Retrieve supporting information

Metadata Workshop Materials

Command (metadata)

In your Conda Shell, issue the following:

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pdal info ./exercises/info/interesting.las --metadata
  • JSON output

  • Tree structure

  • Coordinate system

  • Filter output

Run (metadata)

_images/info-interesting-metadata.png

JSON output of file metadata

Searching Near a Point

Purpose:
  • Neighborhood query

  • Point ordering

Command (near - metadata)

In your Conda Shell, issue the following:

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pdal info ./exercises/info/interesting.las --all | jq .stats.bbox.native.bbox
  • Print all metadata info

  • Find and compute midpoints from bbox metadata

  • Query file nearest midpoint

Command (near - query)

In your Conda Shell, issue the following:

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pdal info ./exercises/info/interesting.las --query "637301.20, 851217.57, 496.49/3"
  • Print 3-nearest points (in order)

  • Output JSON format

Run (near - query )

_images/info-near-point.png