Smathermather's Weblog

Remote Sensing, GIS, Ecology, and Oddball Techniques

Point Clouds – the (re)start of a journey

Posted by smathermather on January 19, 2016

If you have followed this blog for a while, you will notice a continual returning to and refinement of ideas and topics. That’s how the blog started, and this role it has served, as a touch stone in my exploration of topics is critical to how I use it. I hope it is useful to you too, as a reader.

So, let’s talk about point clouds again. Point clouds are like ordinary geographic points — they have X, Y, and Z (typically), but there are a whole lot more of them than ordinary. How much more? Well, instead of thinking in the 100s of thousands, we think more along the lines of 100 of millions or billions of points.

The other thing we need to recognize about point clouds is that they may be n-dimensional — a LiDAR point cloud may have X, Y, Z, intensity, return number, class, etc..

Good Free and Open Source Software (FOSS) tools for dealing with point clouds include a spectrum of projects, including PDAL (Point Data Abstraction Library), and the Pointcloud extension for PostgreSQL (with PostGIS integration, of course).

Previously, I was attempting to process large amounts of LiDAR point clouds in order to model bird habitat. Now that I have the requisite storage, and PDAL has a height calculator, I am ready to dive back into this.

In the meantime, there are some cool things to check in this space. Let’s start with this presentation by Michael Smith on PDAL from FOSS4G in Seoul last year.

Screen Shot 2016-01-19 at 8.32.03 PM

Want to see some of the incredible things you can do in the browser, go no further than here:

Screen Shot 2016-01-19 at 8.34.52 PM.png

This goes deeper than simple vector tile approaches and employs level of detail optimizations that are necessary for this large of a use case. More on this later

postscript 1/20/2016:

Looks like I outed the above project… . Apologies to https://hobu.co for this. For the record and from their site:

Hobu is a team of three software engineers located in Iowa City, Iowa and Cambridge, Iowa. We have been on the forefront of open source LiDAR software for over five years, and we have been building open source GIS software for even longer. We provide open source lidar software systems development, open source GIS software development in addition to contract research and development, systems design, evaluation and implementation.

Please contact us about any of the open source software for which we provide support.

We are the primary support organization for the following libraries:

  • PDAL — Point Data Abstraction Library
  • plas.io — WebGL point cloud rendering
  • Greyhound — Point cloud data streaming
  • libLAS — ASPRS LAS read/write

Welp, there we go, an unintentional public launch. Awesome work though… .

One Response to “Point Clouds – the (re)start of a journey”

  1. […] this series. PDAL as a utility is pretty interesting, so we’ll focus our learnings on PDAL. (Prior posts start here). I may have a build tutorial written for getting through the critical (as contrasted with minimal) […]

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