How?

[Dave Stoll]

My subject line is vague on purpose. I don't know anything about LAStools and I can't find out how to use them. Here's what I know:

Everyone agrees that LAStools is the bomb. But the program is, to me, impenetrably dense and labyrinthine and seems to involve some sort of cryptic DOS programming. I'm terribly ashamed that I seem to be the only human on earth who can't run this program like a boss.

Every data site I go to has either LAZ or zLAS files.

It is not possible to directly use LAZ or zLAS files in AutoCAD C3D or ReCap, the two programs I'd like to use LiDAR in.

Global Mapper can use the LAZ files, easily and intuitively, but my trial version expired, and I'm just not ready to shell out $1K to play with LiDAR.

I would be grateful if anyone could point me to a site, maybe something like "LAStools for Complete Idiots", where I could find out how to convert LAZ to LAS.

Thank you.

Dave

[Martin Isenburg]

Hello,

Thanks for you interest in LAStools for your endeavors. As you have found this group you are well on your way to become a LAZ master soon. Most of the LAStools in the .\LAStools\bin directory have a GUI so a simple double-click will start the tool that you are interested in with a Graphical User Interface - for example laszip.exe. I have attached a few typical GUI screenshots.

If you work yourself through these tutorials you will understand why many people think "that LAStools is the bomb" ... (-:

http://rapidlasso.com/2013/04/20/tutorial-quality-checking/
http://rapidlasso.com/2013/10/13/tutorial-lidar-preparation/
http://rapidlasso.com/2013/10/20/tutorial-derivative-production/
http://rapidlasso.com/2014/03/02/tutorial-manual-lidar-editing/
http://rapidlasso.com/2014/09/02/six-new-video-tutorials-on-lastools/

There are a lot more videos and tutorials available here:

http://rapidlasso.com/category/videos

http://rapidlasso.com/category/tutorials

Or checkout this YouTube playlist of LAStools tutorial videos:

http://www.youtube.com/playlist?list=PL5A2DB97AA32C1A3B

And finally there are the README files for each tool:

http://lastools.org/download/laszip_README.txt

http://rapidlasso.com/laszip

And should you encounter some evil "LAZ clones" (aka proprietary zLAS by the dArc force) there is always the LASliberator to help you free your enslaved LiDAR points:

http://rapidlasso.com/2015/04/20/new-lasliberator-frees-lidar-from-closed-format/

(-;

Regards,

Martin @rapidlasso

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[Mark Seibel]

Hi.

 

I would be grateful if anyone could point me to a site, maybe something like "LAStools for Complete Idiots", where I could find out how to convert LAZ to LAS.

If you have a .laz file, you can use:

laszip -i zippedLAS.laz -o unzippedLAS.las

laszip -h will give some help and examples.

Mark

[Nicolas Cadieux]

Very funny...

The learning curve is very high in cad/gis in general.  We all went through this at some point. 

If you open the lastool folder on the hard drive, and click on LasTools\bin directory, you will find file with the name of the various tools like las2txt.exe.  (make sure the known extension are not hidden in Windows).  If you double click on the file name, a GUI (graphic user interface) will pop up and you can start using it.  That should get you going.  If you open the las2txt_readme.txt files, you will see AL. The command line tools (DOS like interface).  The GUI will help you understand this also as the commands are also written for you.

A good place to start for help is YouTube.  You can also use Qgis with lastools for the work.  Make sure you read the licence.  Lastools has some open source tools but most are not and have some limitations in the free version. 

You can also use cloud compare for some of the work.

Cheers!
Nicolas

[David Brubacher]

You will also have a bigger problem soon, Dave

C3D is practically unusable with clouds beyond 50,000 points. You need to aggressively decimate the redundant data without losing the character of the site your cloud is modelling. I've found that to be by far the hardest part of using cloud data in C3D. You will also wish it had a filter to hide contours that enclose too small an area. Your results will be ugly until you get things figured out.

[Dave Stoll]

Hi Dave,

I was just about to give up on LAStools, and then among Martin's links I found his "Nubes de Puntos y Aplicaciones en Ciencia" video. Title in Spanish and 5 hours long, I first thought Hell No. But I put on a pot of coffee and within the first few minutes I was hooked to the end. Breakthrough!

Agreed, Civil 3D seems woefully inadequate for LiDAR. If Autodesk doesn't wake up soon and smell the GIS, they're going to lose customers by the bucket loads to free and reasonably priced software like QGIS and Global Mapper.

Dave

[Wes Toews]

Recent versions of C3D have gotten much better at handling point clouds. They involve a lame indexing preprocess but once you get past that, you can view full clouds by intensity/echo/color, all that stuff and build a ground model from ground points. Basic but better than it used to be.

[Dave Stoll]

Thanks Wes. I'm using C3D 2016. I had played with LAS point clouds a bit in C3D, but my biggest problem was the lack of LAS data. Most everything available is either LAZ or zLAS, so that's why I was interested in LAStools. Today I finally became comfortable with LAStools. If I could figure out how to "Liberate" zLAS files, my happiness would be complete.

Dave

[Wes Toews]

Well that's a different question! See here:

http://rapidlasso.com/2015/04/20/new-lasliberator-frees-lidar-from-closed-format/

For a link to the tool to do so. Someone else might know a better link (?)

[Dave Stoll]

From our favorite Hall-of-Shamer, Slovenian LiDAR:

http://gis.arso.gov.si/evode/profile.aspx?id=atlas_voda_Lidar@Arso

​

Dave

On Sun, Mar 20, 2016 at 1:32 PM, Dave Stoll <undergroun...@gmail.com> wrote:

Thanks Wes. I've got it loaded. I just can't figure out how to use it. Clicking "Liberate" doesn't seem to do anything.

Dave

[Wes Toews]

It returns silently, so you get the output files in LAZ or LAS in the same directory without a progress bar or 'Finished!' popup...unlike the original ESRI tool which lets you go compressed to uncompressed (zLAS->LAS) but not the compressed to compressed (zLAS -> LAZ) conversion.

[Dave Stoll]

Wes,

I've tried this dozens of times and I get NO result in that folder or any other folder. The ESRI tool also doesn't work for me. I'm sure since neither tool works for me that it's something I'm doing wrong. Is there a video out there somewhere that clicks through things step-by-step?

Dave

[Wes Toews]

It's hard to say then...I literally just downloaded both programs, unzipped them, grabbed a 40mb file off that Slovenia site you provided and converted to laz and las no problem with both (as capable).

No error messages pop up with either program?

Las liberator command line doesn't give any messages?

For me the esri tool defaulted to some temp appdata folder, maybe double check the output path?

Or maybe it's a problem with the zlas file...have you tried redownloading it?