One of the first things I did when I began working with lidar-based elevation models back in 2006/2007 was to think about how to best visualise these data to be able to discern sublte surface morphology. The “standard” shaded relief just didn’t convince me, and of course I wanted to get as much as possible out of the data. So I started developing algorithms and writing simple software tools to implement them. When I started working full time with lidar data in 2009, I had to upscale this a bit and add some data management and automatisation. Still, these tools were meant to be used for one particular project (the archaeological prospection of Germany’s federal state Baden-Württemberg; since 2010 with support by the European Commissions’s Culture Programm through the multinational project Archaeolandscapes Europe), and I was the only person working on the project. It didn’t matter that I had to make changes to the code every now and then. The amount of code grew step by step: I saw a poster about sky-view factor visualisation at the AARG conference in Bucarest in 2010, came back and added it to the other algorithms. I had other ideas or found interesting algorithms in the literature and added them. And so on.
Once in a while people would ask me if I could process data for them or if they could get the software that I was using. What software? The software I use for the project was (and still is) a makeshift collection of tools implemented in VBA under MS Excel, with a dedicated user interface showing a map of Baden-Württemberg, all the data directories and many of the parameters written directly into the code and the geocoordinates coded into the file names. Works fine for me, but it isn’t portable at all. It would not work on a different computer, and it would be a lot of work to adapt it to a different project.
With the obvious demand for a software which I could share with my colleages, I finally decided to create a portable stand-alone software in which all the visualisation algorithms would be implemented. Easy enough, just take the code from VBA, adapt it to VB2010, tidy it up and, voilá, create an executable. Well… it wasn’t quite that easy. Creating a software that others could simply download and use turned out to be quite different from just writing some code to implement one or another algorithm. And it took much more time than I had expected. Finally, there was some pressure to finish and release at least a beta version, because I had promised to give a software/visualisation tutorial (using my software) at the CAA Workshop in Berlin in January.
Coming back from that workshop, I was inspired by Hubert Mara’s talk to add yet another visualisation technique: multi-scale invariant integrals. And finally, it was decided that what had by then been named the Lidar Visualisation Toolbox (LiVT) was more or less ready to be published at http://sourceforge.net/projects/livt/as open source software under the GNU General Public License. It’s still very much a beta version, and the code is certainly not as tidy as I would want it to be. But finally it’s out there, and if anyone is willing to help improve it, just let me know!