Point Cloud Classification

[Mike.M.Carlson]

Apparently Autodesk does not offer options for those of us wanting to classify point cloud data?  I didn't see an option in ReCAP either amazingly?  Please correct me if I'm wrong though. 

If there isn't an Autodesk AEC option, can someone recommend 3rd party options that would do a good job classifying sUAS point cloud ground data?  

I just used the Pix4D engine to process the drone data and chose the option to classify the resulting .las files...it did ok, but was hoping for a better result.  

Thanks in advance.

[rl_jackson]

Pix4D is most likely the best your going to get without going to a full fledged survey drone made by Trimble or Lieca. The issue is that once you have the las file is that you need to import to IW and have it weed just the ground data which results in a gridded surface vs a true TIN. IMO the work flow (adesk chose for us) is the problem since they decided to remove cloud funtionality from C3D (or at least bury it in Map). Just my take on it. Not sure what they where thinking

[Anonymous]

Welcome to Lidar Hell!

What used to work doesn't!

Recap is a waste of time, has a very hard time understanding that I work in feet and adds no value other than a proprietary format and time.

Map thoughtfully moves everything to meters for me if I have a classified LAS.

Infraworks doesn't appear to understand classified LAS.  Wants to do it itself with cloud credits.

All understandable from AutoDesk's point of view, but not the user.

Enjoy!

[Anonymous]

I guess I should mention QGIS, which has does some classification stuff, if you are DYI.  Complicated, but doable.  Also free, other than your time learning and kludging.

[autoMick]

Yes it is a shame that Recap doesn't do it.

I've used Pix4d for this and it was and it was OK. I noticed that Agisoft Photoscan also does auto classification but I haven't used it.

What is the variety of terrain you are trying to classify? Are your photos good and using the same white balance? Auto white balance is the devil. I'm assuming you are actually trying to classify a point cloud generated from photogrammetry rather than LiDAR?

Cheers

Mick

[dgorsman]

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@rl_jackson wrote:
Not sure what they where thinking

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Point clouds used to be the (almost) exclusive domain of civil work, but these days it's in far greater use in other fields e.g. media/entertainment and "reality capture" of facilities and archeological-scale objects.  There wasn't even distribution in implementation between products, either, so ReCap now gets used as a common front end rather than each product silo spending their own resources.  In the expansion to handle other users though, civil users kind of got left behind.  I would recommend visiting the ReCap IdeaStation and adding a vote for ideas like this one if you haven't already:

https://forums.autodesk.com/t5/recap-ideas/add-some-basic-civil-design-features/idi-p/7586560

(and yes, banging my own drum a bit there  ).

[AllenJessup · Accepted solution]

From Dotsoft: CIVIL3D LIDAR STRAIGHT TO TINSURFACE

                        CIVIL3D IMPORTING LIDAR (LAS) FILES

[_Hathaway]

We tried using Recap simply because it was an Autodesk product that we already had but had never had the opportunity to use it.  After wasting many days worth of time we determined it to be a terribly designed product for land surveyors.  The interface is bad, beyond bad and the coordinate system issues are not even remotely intuitive or functional.  It can be done but it is a huge huge headache.  We moved our drone processing to a pix4d-virtual surveyor combination and haven't looked back.  We also abandoned the whole point cloud thing altogether and focused on densifying our TIN with tighter grided export data.  

Don't get me wrong, we would love to be able to do all this within our Autodesk software and will continue to monitor any advancements in ReCap...until then....

[Mike.M.Carlson]

Thanks everyone for your responses.

I was having mixed results with my 130acre drone photogrammetric data set over the weekend.  My AOI is attached for those interested).  Lots of elevation relief.  Used a Phantom 4 Pro and Trimble R8-3 rtk-gps to set GCPs.   

After processing the 1146 images in pix4D, I did the default point classification in Pix4D.  Then I imported 5 .las files outputted from Pix4D into ReCAP 2019 to process for eventual inclusion into C3D19.

I first tried to use the DotSoft C3D Tools Mass points on the raw .las files mentioned above to build a quick surface from the classified ground shots, but I got an error (maybe my sets were too big).

So then I used mapcreatepcsurface command after inserting an overall combined ReCAP .rcs point cloud into the drawing. This command built a solid GeoTiff from the classified ground shots. However, the DEM surface you get from the GeoTIff in C3D is enormous and you can’t simplify the surface via C3D surface edit because it is a DEM grid surface. You can’t even export to LandXML to bring it back into C3D to simplify either. However, once this surface was in C3D, this surface closely matched the formal aerial survey we flew early in the year. Flat areas and side slopes looked with 3-6” or better. But the dwg file size is almost unusable.

I also tried the Infraworks engine to process the overall ReCAP file and exported out an “Optimum” .IMX of the resulting terrain surface to C3D. I then compared the processed terrain surface vs. the Point Cloud in Infraworks and I could see reasonable attempts to exclude man made structures.  I was very happy in Infraworks until I checked against the formal surveyed surface in C3D. Did the same checks against the formal survey surface, and noted more error on side slopes than I would like. The .imx data was parsed and easier to work with in Civil 3D though, so that is a plus, but I don't trust the output despite it looks pretty in Infraworks.

It looks like I need to do research on 3rd party platforms (off the Autodesk ranch) to both auto-classify point clouds from Drone imagery and get something that has processing options on the back end to allow the resulting surface to be down-sampled or parsed, but accurate enough to be usable for design and earthworks.

 Thanks again for everyone's input.

[TerryDotson · Accepted solution]

I first tried to use the DotSoft C3D Tools Mass points on the raw .las files mentioned above to build a quick surface from the classified ground shots, but I got an error (maybe my sets were too big).
At 73 million (ground) points (out of 85 million total) you hit a 2gb memory limit on a single list.  However, we've been working on this and think we have found a way around it (by feeding bucketfuls instead of the whole barrel at once).  However no matter how you stuff it, Civil3D is not going to respond well to that much data.

[Mike.M.Carlson]

Thanks Terry.  It's certainly not a dotSoft issue.  I love your C3D tools.  It's a problem with my dataset size.  I need to figure out a way to dwindle this down before bringing into C3D.  Thanks for your help.

[Anonymous]

You should try Pointerra! We take all files formats for pointclouds (Las,LAZ, e57, RCS etc) upload the data to our secure online portal and easily, manage, host, share, classify and use the data and send directly to all Autodesk authorising solutions.click here to view B84yubo8TmiYTtoGzHsUEe

http://blogs.autodesk.com/recap/beyond-the-point-cloud-with-pointerra/

[Mike.M.Carlson]

Thanks Terry,

The DotSoft Civl 3D Tools updated Mass Points Tool worked very efficiently when using the "Throw out" and "Tolerance" parameters you recommended on the classified ground .las files.  It took a little over 12 minutes to build the surface, but am very happy with the ease of the workflow and the QA/QC results. 

Please note that I ended up revising the point cloud in pix4D to cleanup the erroneous point cloud classifications the "Auto" classification method churned out on the first go-a-round.  It added more ground shots, but overall the Point Cloud looks much better.  Combine this with the fact that I won't have to use the previously mentioned ReCAP/Map 3D mapcreatepcsurface command to GeoTiff to DEM surface workflow, I'm super happy.  You even gave me an option to parse the .las data to keep file size manageable...all in one easy to use tool...well done sir!

Thanks again to everyone who chimed in.

[gustavo.bergoya]

Hi group,

In infraworks you can classify point clouds of drone and export this point cloud to Civil 3D.

Regards

[Anonymous]

I'm also one of the dissapointed users who since C3D 2018 no longer can use classified point cloud data properly.

For me (as a consumer of classifed pointclouds, not a creater) the problem is that Civil3D cannot build a TIN surface anymore based on point classification. This used to be possible in 2017 (very buggy, but still). Now I can get a pointcloud with buildings, trees and ground perfectly classified but using the command to build a surface for existing ground in Civil3D does not allow me to filter out the buildings and trees. 

We can visually filter out the unwanted points when viewing the PC but the created surface swallows all the points regardless. It's a critical mistake on Autodesk's part and I'm sure it was unintended, but it's way overdue to fix this so we get back basic functionallity.

 @lim.wendy

[TerryDotson]

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Civil3D cannot build a TIN surface anymore based on point classification.

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Actually it can with a little help.   Grab the free DotSoft LidarTools from the Autodesk App Store and you can select multiple LAS/LAZ files, specify the classifications (typically 2 = ground) and a rectangular area of interest to create a TinSurface directly from those files.  Civil3D creates the TIN, we just feed it the right points.  Also contains other useful tools to draw lidar file extents with labels, list the header information from multiple files and more, all at no charge.

[autoMick]

@TerryDotson thumbs up!

I occasionally use this tool and it is a quick painless way to achieve most of what Autodesk decided to take out of Civil3d. I particularly like how you can set the area of interest and the tool will just grab the data it needs from a whole directly full of laz files.

Mick

[jsupanichUBKHA]

That's Autodesk for ya. "We are going to let you filter the points in a dozen different ways and then add them to a surface model let you VIEW them."

Thanks

[rl_jackson]

@jsupanichUBKHA you must be missing Recap on your PC since it Classifies data. Hit a search here and you'll find raves about @TerryDotson C3D Lidar Tools. Help yourself be productive, check those out along with Infraworks.