QGIS 4 Arch - LiDAR to DEM with LASTools

[@ivanalexafrench]

Amazing! I've been using ArcMaps (student account) but couldn't open an laz file so I downloaded QGIS and was very overwhelmed. Now I have my contour data! Thank you so much 🙂

[@ArchaeoSquatch]

Hey, that's great! Glad the video helped out! :)

[@kdbryant77]

Once again, thanks for putting together a clear and concise tutorial for converting LIDAR to DEM.

[@ArchaeoSquatch]

And thank you for watching! Please, keep in mind some of my other videos explore alternative ways, I'm particularly found of cutting LASTools out of the equation and doing everything in CloudCompare. Of course, that's personal preference! :)

[@moendopi5430]

I don't know if anyone else had this problem, but I think it is important to mention that the LASTools zip/folder needs a file path with no spaces. For Instance don't stick it in a folder named LAS Tools. I kept wondering why the tools didn't go anything before I realized in the log it was saying my file path didn't exist and noticed that the path was truncated because of a space. Might be obvious for long term GIS users, but I hadn't run into this issue in so long I hadn't forgotten about it.

[@northof4912]

That is often a problem with GIS, even worse, some paths in ArcInfo cannot use either a dash or underscore, can’t remember which - it’s not consistent though. Best to avoid all those.

[@alanmcrae8594]

Liked & subscribed! Interested in LIDAR mapping and converting point clouds into various models that can be used for planning homestead development, permaculture food forests, ponds, drainage & irrigation systems, and infrastructure. Thanks for this clear video presentation.

[@hobbymichael]

Great Help, thank you !.

[@roberttheberge1966]

Incredibly helpful video, thank you!

[@ArchaeoSquatch]

Great! Glad it is helpful. Also, check out my videos about processing LiDAR with CloudCompare alone. An alternative workflow that produces good results, and a totally open source solution as well!

[@charleshartlen3914]

Thanks so much for this content. Really nice video!

[@MatteoCarrati]

thanks this was so helpful

[@francisagreement1781]

This tutorial was posted like 4 years ago, I don't know if I can get quick help here. My QGIS doesn't have Las2demPro, how can I get that?

[@ArchaeoSquatch]

Yeah, been a while, will eventually remake these. When I do, I'll drop the LASTools video and either focus on QGIS's LiDAR tools, or the combo of CloudCompare and QGIS. Fortunately, I do have a video on using CloudCompare and QGIS! You can find it here: kzbin.info/www/bejne/m4jSXnarid-fr9ksi=AJQEKABA3WQhn9F8

[@sudipdey3]

Thank You Sir

[@ArchaeoSquatch]

You're welcome!

[@sudipdey3]

Sir Hope We will Getting this Types of Tutorial more...by Your Quick Easily process... Thanks sir

[@MrLikeidontcare]

kudos to you sir. nice video!

[@ArchaeoSquatch]

Thanks!

[@Tylhuynh06]

I love you man!

[@ArchaeoSquatch]

Thanks!

[@MrEdoslav]

Really useful- Thank you! :)

[@ArchaeoSquatch]

You're welcome, glad to hear it!

[@lutherbrown8873]

thanks for this. do you know if LAStools can extract a DEM from a TIF file?

[@epicureanstoic5723]

Outstanding video! Would have saved me dozens of hours had I seen it earlier, and now works great. I had been trying to use 3DEM to create DEMs from LAS files, but it puts 17N UTMs in Nicaragua instead of the US.. this works a treat, wonderful and you covered it all. I am curious, does the geo location data reside in the DEM file, or one of the other files? The LAS file contains the CRS data, which you pulled up in first part of the video using lasinfo, but I Am curious about where it stores DEM files? I am using this for lasered maps and 3D prints, so I'm not GIS savvy. thanks again!

[@epicureanstoic5723]

hey I figured out that 3Ddem actually works fine. I just needed to extract the CRS information and apply it to the DEM layer that I generated in 3DEM, and all is well, FYSA it saves like a ton of steps to just use 3DEM and convert each LAS over to DEM, then merge. 3DEM doesn't use laz's tho. have to d/l LAS.

[@ArchaeoSquatch]

@@epicureanstoic5723 Apologies for not getting back sooner, but glad it worked out! :)

[@patriciaoneill3086]

Around 3:50 where should the downloaded LAZ file be saved so that it can be found in QGIS? Is there a folder within the LAStools folder (saved in my Applications, as I am using a Mac) that these should be saved in so they can be accessed, or can I just make one for them wherever? The latter approach has not worked.

[@ArchaeoSquatch]

I'm not familiar with Mac computers, but using a Windows machine you can save the downloaded LAZ/LAS files anywhere on your hard drive.

[@MohiuddinImran]

Thank you so much!

[@ArchaeoSquatch]

You're welcome! Glad it was useful. :)

[@mattsanders594]

Great video. Thanks!

[@ArchaeoSquatch]

Thanks!

[@lostshun]

Hello! it is a wonderful tutorial! I have a question though. The compiled tif does not seem to have any data (it looks like a plain black square). But the splitted .LAS files have all the needed data in it. Do you have any idea why? I really need the Geotiff compiled. Thank you!

[@ArchaeoSquatch]

Thanks! I'm not sure what's happening with that, might be an issue with the setting. You might also try to use my other workflow for LiDAR data, here's a link to the tutorial: kzbin.info/www/bejne/m4jSXnarid-fr9k&si=EnSIkaIECMiOmarE

[@marc-andrepetit5277]

Thank you! Great info!

[@ArchaeoSquatch]

Thanks for watching! Glad it was helpful. :)

[@Hannesorama]

Any alternative workflows now that lassplit and las2dem are licensed?

[@ArchaeoSquatch]

Absolutely! Use CloudCompare! :) I have a tutorial for that - kzbin.info/www/bejne/m4jSXnarid-fr9k

[@wreqeh7682]

When trying to produce LAZ files and produces LAS (split files) the LAS doesn't produce for me?

[@AbidAli-bv2gl]

Excellent

[@ArchaeoSquatch]

Thanks!

[@aaroncolgrove537]

Can someone please help me with the issue that moendopi mentioned? For whatever reason LASTools is not processing the data correctly when I select a .laz file for lasinfo or lassplit. All I get is an error about the file path not being correct.

[@ArchaeoSquatch]

A couple of things could explain this. This could be that LASTools is not installed correctly, which is covered in the video (make sure it is in the correct location and that settings is set to that). Sometimes, I think having the .laz/.las file in a path with spaces (e.g., C:/Users/Name/All LiDAR/) can cause an error. Honestly, I now recommend folks use CloudCompare. I have a very nice video about that workflow here: kzbin.info/www/bejne/m4jSXnarid-fr9k

[@AK-me3vb]

Thank you for the video! I have a question about the coordinate system. When loading the merged DEM-dataset, my layer doesn`t show a coordinate system. What's the reason and how can the problem be solved?

[@GreenMountainGoldTrap]

Thank you! I have been trying for close to two years to get Lidar to work. Just found QGIS on Jan 3rd but wasn't sure if I could use it in the same manner as Saga Gis. This was extremely helpful however, because it was a city setting I can't help but wonder if the program is indeed going to show me in detail all Bedrock crevices, pockets and or trenches buried beneath substantial amounts of overburden. So that's a question. Also, is Lidar and Dem basicly the same thing image wise?

[@ArchaeoSquatch]

Thanks for watching and the comments! So, I don't think LiDAR will show geological features (bedrock crevices, etc.). Basically, all LiDAR will record is the surface, and nothing below the surface, unless it impacts the surface landscape. So, a crevice will show up if it continues to the surface. Otherwise, you might try looking into infrared satellite imagery, which can often record subsurface features. Unfortunately, that's outside my area of expertise, but I suspect it would be a specific band combination like those discussed in this article about detecting subsurface lakes in Greenland (www.frontiersin.org/articles/10.3389/feart.2017.00058/full). I do have a video tutorial on using Sentinel imagery (as well as Landsat), which might help get you started? That link is kzbin.info/www/bejne/d2qcoYCsaah5jck Apologies if I don't understand the question! :) To answer you other question, LiDAR is a 3D cloud of points, typically classified into different categories (ground, vegetation, buildings, water, etc.). A digital elevation model (DEM) is a raster dataset, basically a 2D image showing a subset of the LiDAR point cloud. As such, a DEM only shows the ground surface, by estimating the elevation of missing areas (ares without points) and removing all non-ground points from the classification process. Hope that helps!

[@GreenMountainGoldTrap]

@@ArchaeoSquatch You have answered my question quite well. Yes, the crevices I am looking for would be on the surface. Just buried under a lot of overburden. As stated, I have been trying to figure this out for almost two years in search of a trench I know exists. A trench that is going to hold the gold I am always on the hunt for! Thank you for the additional info as well. I will surly look into it. I truly enjoyed your video because you left no rock un-turned as to how it works. Well done! Most don't go into such detail.

[@neilfalconer4754]

Thank you for this tutorial, much appreciated. When merging the individual DEMs back into a single TIF, will the Merge tool interpolate across the edges of each small DEM to ensure a properly "blended" finish across each edge?

[@ArchaeoSquatch]

In my experiments it seems that good LiDAR (lots of successfully classified points, etc.) doesn't introduce much error because no additional spacing is introduced between the points across different files. This is only a problem with LiDAR of lower quality (poor classification, etc.). Of course, then error is introduced across the data, especially when points are poorly classified. I've had good experience re-classifying ground points using MCC-LIDAR (sourceforge.net/projects/mcclidar/). I am planning a video on that as well. Hope that helps!

[@beverleyfalconer2145]

@@ArchaeoSquatch Thank you for your feedback. I guess the way to check for "artifacts" would be to plot conours and check if there are any "blips" along the edge of each joint. However as you indicate its likely to be negligible.

[@colo5260]

I am having a difficult time getting LasTools to run on a Mac using QGis. Do you have any recommendations?

[@ArchaeoSquatch]

I don't use Macs, but many of my students do. My understanding is that LASTools will not run on a Mac unless you use Wine or some other method for running Windows programs. UBC Geospatial Resources has a page describing the process, but it is 3 years old now - gis.ubc.ca/tutorial/installing-lastools-for-lidar-data-in-qgis-for-mac/. I created this video when I was still using LASTools, but in the past year I have fully transitioned to CloudCompare for all my point cloud processing needs, including working with LiDAR. I created a video that only uses CloudCompare and QGIS - kzbin.info/www/bejne/m4jSXnarid-fr9k. Hope that helps and thanks for watching!

[@colo5260]

@@ArchaeoSquatch Thank you so much for your advice. I am running into a world of problems trying to get Cloudcompare to work on either a PC or Windows program. It seems Windows 10 didn't have the MSVCR120 file in their systems folder. Downloading it and installing didn't help. With a Mac there was an issue reading the data type as well, some online threads pointed to the laz/las format the USGS or NOAA puts out as 1.3 which people were saying cloud compare couldn't handle and it somehow needed to be downgraded to 1.2 - I am not sure how to proceed. Your videos are super helpful, I just can't get much of the programs to work. The only workaround for now is through ESRI but I am looking for an open source option, and one that works very much like cloud compare. Thank you again for your response. On a side note, what PC operating system are you running? I am wondering if some of this is an OS issue?

[@klaragunnarsson8549]

Hi! Thank you for a very useful video :) I wonder, I want to create a DEM and a DSM, but it seems to be the same process when I search on it. Do you choose class 2 in the Las2demPro to get the ground points? How do I generate a surface model on the same data set? All the best!

[@ArchaeoSquatch]

Honestly, I'd recommend using CloudCompare, here's my video on creating DEM and DSM from lidar - kzbin.info/www/bejne/m4jSXnarid-fr9k

[@davidesalaris8199]

Hi, thanks for the videos. I was wondering if you know where I could download LiDAR for Middle East and Central Asia (my field of study in Archaeology is about these countries)

[@ArchaeoSquatch]

Oh wow, that's a tricky one. I don't know of any sources, and usually can't even find it for my projects in the Caribbean either. Depending on what you're looking to do, perhaps the SRTM data will be sufficient? Here's a short video on using it - kzbin.info/www/bejne/np_Iqq1nrtecgbs

[@davidesalaris8199]

@@ArchaeoSquatch thank you for you quick response.

[@joshuah.9687]

Downloaded a tile in Georgia from USGS TNM download, but the Lasinfo had no data on the .laz file. Thoughts? thanks

[@ArchaeoSquatch]

Hmm, not sure what that means exactly. Perhaps try processing the LiDAR with CloudCompare using my other video - kzbin.info/www/bejne/m4jSXnarid-fr9k

[@joshuah.9687]

@@ArchaeoSquatch The issue ended up being a plugin maneuver. Once I got that sorted out, I was able to follow along, except now my processed DEM came out flat. 0 to 0 elevation, so now I just have a large grey brick. Maybe something missed or unchecked?

[@joshuah.9687]

BTW, this is lidar data directly from USGS TNM, so I would think (hope!) that the data is good.

[@joshuah.9687]

@@ArchaeoSquatch Running lasinfo again, I'm seeing what appears to be the issue: number of points by return: 0 0 0 0 0. Could this be the issue? There are 1.2mil points on first return though, but there are 3 warnings: WARNING: for return1 real number of points by return is 1204031 but header entry was not set. Any and all help much appreciated. Cheers!

[@pseudomorph_geospatial]

The LAStools download site has changed since you made this video. Where can I get it and is it free?

[@ArchaeoSquatch]

Thanks for the comment. I'm not sure what will happen with LASTools now that the developer has passed away. You can still download them from here: rapidlasso.com/lastools/download/ (I've updated the video's description as well). In all honesty, I prefer a non-LASTools workflow now, which you can learn about in my other video here: kzbin.info/www/bejne/m4jSXnarid-fr9k. Hope that helps!

[@pseudomorph_geospatial]

@@ArchaeoSquatch thanks for the reply! I got it.

[@krishna0506]

great learning, thanks for sharing, I was tying similar way on mac but unfortunately getting error with lasinfo, lassplit, LAStools console output /bin/sh: C:LAStools/bin/lasinfo: No such file or directory -- tried to check the path, but seems LASstools not allowing me to set path in Qgis, could you help me in this, installed wine too but still not identified.

[@ArchaeoSquatch]

Thanks for the comment. Unfortunately, I do not have access to a Mac computer. I did find this from the University of British Columbia, it may help even though it is a couple of years old - gis.ubc.ca/tutorial/installing-lastools-for-lidar-data-in-qgis-for-mac/.

[@krishna0506]

@@ArchaeoSquatch Thanks for quick reply.

[@jokyeonghun7474]

Thanks for this video. But I have one question. I have Unicode DecodeError: 'utf-8' . How can i solve this problem?

[@ArchaeoSquatch]

Without more details this could be hard to troubleshoot. You might want to uninstall and reinstall any plugins you are using. Also, starting with a clean profile often fixes this issue (according to some online forums). To fix this, click the Settings drop-down menu and highlight User Profiles. Then click New Profile and name it whatever you want. You may have to re-start QGIS. But, this often fixes issues like this for me.

[@drewsims5295]

I keep getting a response when using LASinfo that says file path not found. But both my project and las file are both on my desktop. Any suggestions?

[@ArchaeoSquatch]

This is likely because you've placed the LASTools folder/files in a different location than discussed in the video (see Installing LASTools section). This is a common mistake, I recommend saving this folder to you C: drive, that will fix the problem. Alternatively, follow the instructions in the video to point the LASTools within QGIS to the location on your computer where you saved the folder.

[@kdbryant77]

Thanks for the great tutorial. I'm having trouble locating the site to buy the paid version of LAS Tools. Can you help?

[@ArchaeoSquatch]

I've not purchased a license myself, but you can find information about that here - rapidlasso.com/pricing/

[@edoardo5330]

Why keep_class2 filter? I prob missed something. Thanks so much btw!

[@ArchaeoSquatch]

Its probably not required since you've already removed the other points, but class 2 points are those classified as ground points. I do it as an added security step to make sure only ground points are used. :)