Newbie Question - Importing a .las model

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matthewgreaves
Posts: 1
Joined: Thu Apr 13, 2017 4:28 pm

Newbie Question - Importing a .las model

Post by matthewgreaves »

Apologies if this is posted in the incorrect place. I'm hoping that someone may be able to help.

I am trying to load a .las model exported from DroneDeploy and am experiencing some strange behaviour.

On initial load into CloudCompare I am seeing the model (albeit after zooming in a lot) looking as I would expect. Once I try and change the perspective it seems to 'explode' and all of the points then are basically a long line.

The .las file contains just over 29m points and loads OK in Quick Terrain Reader.

I am loading the file with all system defaults and system suggested shifting and scaling.

Any suggestions gratefully received!

Thanks,

Matthew
Miner_jeff
Posts: 4
Joined: Fri Aug 04, 2017 4:26 pm

Re: Newbie Question - Importing a .las model

Post by Miner_jeff »

Hey Matthew,

Any luck with the long string of vertical points? I am attempting the same and seeing similar results. Can you share your resolution?

Cheers,

Miner_jeff
daniel
Site Admin
Posts: 7332
Joined: Wed Oct 13, 2010 7:34 am
Location: Grenoble, France
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Re: Newbie Question - Importing a .las model

Post by daniel »

"Funnily", I totally missed the first post :)

Are you applying the global shift when suggested by CloudCompare? (to avoid losing precision and messing with OpenGL).

Otherwise I would be interested to get a sample file to try to reproduce the issue on my side.
Daniel, CloudCompare admin
Miner_jeff
Posts: 4
Joined: Fri Aug 04, 2017 4:26 pm

Re: Newbie Question - Importing a .las model

Post by Miner_jeff »

Hello Daniel and Matthew,

I thought I would post my solution back here to help others. I am also trying to load a Dronedeploy .las file.
The point cloud data from Dronedeploy are Lat long decimal degrees. I converted my 1.8M points using an excel spreadsheet I found here: https://www.uwgb.edu/dutchs/UsefulData/ ... sions1.xls, not sure how long it will remain at that location.
I did a quick smell check on the output by plotting the results with an online mapper for utm coordinates. My resultant data plots correctly using a UTM coordinate plotter. found here: (http://www.hamstermap.com/quickmap.php)

I am not affiliated with any of the companies listed below in any way other than being a user of their software.

My work flow is as follows:

Convert .LAS file to .txt using las2txt (http://lastools.org/) http://www.cs.unc.edu/~isenburg/lastoo ... tools.zip
Split large .txt file using Notepad++ into 500,000 line files so MSExcel performs reasonably.
(https://notepad-plus-plus.org/repositor ... taller.exe)

Convert data to UTM Cartesian coordinates for Zone 20 (relevant for my dataset). Using the excel file mentioned above.

Copy and paste MSExcel computed Cartesian coordinates into text files. I used 500,000 lines.

Load into CloudCompare.

With this sequence I do not get colours of the point cloud from Dronedeploy. I can live with that.

Daniel sir, thank you for sharing your hard work with the world. It has helped many of us so much. It is indeed a great tool and very generous of you.

I hope these instructions help others.

Cheers,

Miner_jeff
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