Trouble converting and importing .las LiDAR file

Answered

January 08, 2017 17:39

I have a .las file of an aerial LiDAR scan I'm trying to get into Reality Capture. I can open it in Autodesk Recap 360 and export it as a .e57 file. I can import and view this .e57 file in Faro SCENE fine. When I try to import the .e57 file into Reality Capture after alignment it only builds a very small section of the data.

I know the .e57 import capability is in Beta but I'm trying to figure out if there's a working flow to get .las files into Reality Capture. Here's the original .las and .e57 files:
https://www.dropbox.com/sh/8b7rdre36lbi ... lPjYa?dl=0

Any help would be greatly appreciated!
Thanks,
Dave

762lidar_data.jpghttps://www.capturingreality.com/forum/download/file.php?id=7622097281imageFile jpg

lidar_data.jpg
763faro_e57_import.jpghttps://www.capturingreality.com/forum/download/file.php?id=7632097281imageFile jpg

faro_e57_import.jpg
764e57_import.jpghttps://www.capturingreality.com/forum/download/file.php?id=7642097281imageFile jpg

e57_import.jpg

Comments

11 comments

Wishgranter

January 08, 2017 19:15
Hi David
For now only ORDERED POINT CLOUDS are supported. LAS files are UNORDERED POINT CLOUDS and cannot be converted to ORDERED POINT CLOUDS. So even though you have proper E57 file format, the data structure is not compatible with RC for now....
In short, only terrestrial laser scanners are supported for now.
bckface

August 10, 2017 12:36
Hi Wishgranter

Could you please explain how ordered point clouds are different from other point clouds or rather what workflow one needs to use to make sure it is ordered.
I have a Faro TX5 focus 3d terrestrial scanner with Trimble Realwork and/or Recap, exporting .e57 out of either of these does not seem to be working though.

Thanks
Jason
ShadowTail

August 10, 2017 15:00
https://www.researchgate.net/figure/277572941_fig1_Fig-1-Ordered-point-cloud-top-and-unordered-bottom

The linked website has a picture that shows the difference between ordered and unordered point clouds.
Wishgranter

August 10, 2017 17:09
Hi JP stapleton

Ordered pointcloud -> every scanner have stored its scanning position + additional info, so you can export the data as per scaner position separately. PTX ( can export ONLY ordered PCDs ) or E57 (E57 can export with multiple options and can contain even unordered PCDs )

Unordered pointloud -> just simple "dumb" pointcloud, result of merging ( not mandatory ) multiple scanner position in single cloud. LAS, PTS, PTC, XYZ and etc.

I have a Faro TX5 focus 3d terrestrial scanner with Trimble Realwork and/or Recap, exporting .e57 out of either of these does not seem to be working though.

Hard to say more as not know your workflows, its look like you create one unstructured PCD and export it as E57
Why are you not using FARO Scene sw ?
bckface

August 11, 2017 10:18
Hi guys

Thanks for feedback.

Wishgranter, Im using Realworks as it came as a package deal with my scanner, im starting to regret that now as it seems like Faro scene is a better option.

I am extremely interested in RC and specifically the ability to tie in scanned data with photogrammetry and actually have several current jobs that I can apply this to.
Admittedly I have not completely figured out how to get lidar point clouds into and viewable in RC but the photogrammtry workflow, speed and precision is awesome!

Is PTX export from Faro scene the most stable workflow for point cloud into RC currently?

J
Wishgranter

August 11, 2017 10:59
Hi JP stapleton

Is PTX export from Faro scene the most stable workflow for point cloud into RC currently?

Yes except the export speed of PTX files ( 5MB/sec max ) so E57 from Faro Scene are even better option.

You can use Faro Scene for 30 days as trialware...
stevenramsey123

August 15, 2017 10:31
For the time being you will need to export the scan as a PTS file (just an unordered asci format) and use a PTS to PTX convertor with the Fake scan position being some close to the center of where the scans was collected. this will import fine in to RC
Wishgranter

August 15, 2017 12:40
Hi stevenramsey123

im AGAINST this way, there will be issues with occlusion and etc. its BEST if the data are exported proper way as it should be done...
bckface

August 18, 2017 09:12
Hi Wishgranter

I managed to get PTX exported from Realworks and imported into RC and I must say the mesh creation from Lidar point cloud is incredible!
For my one test project the photo pointcloud and lidar point cloud registered find via align images.
However for a larger test project(building facades) this does not seem to be working. Am i correct in saying that i can use control points from the photos matched to control points on the lidar images to generate match? and that if they are correctly matched they both be added to a new component?
Or must one generate mesh from lidar then register this via control points to photos?

Im in the process of getting a Faro scene trail but they are taking there time getting back to me.

Regards
Jason
Wishgranter

August 18, 2017 17:32
Hi JP stapleton

However for a larger test project(building facades) this does not seem to be working. Am i correct in saying that i can use control points from the photos matched to control points on the lidar images to generate match? and that if they are correctly matched they both be added to a new component?
Or must one generate mesh from lidar then register this via control points to photos?

Mostly its problem of different GSD on laser and images, if its too different then its not working and only GCPs can help there.
If you do properly the photogramemtry part ( overlap, angles, sharpness and etc ) then laser need the same. dont expect miracles if you have too distant placed scan positions ( separation between positions - changing GSD ) that it can align properly on photogrammetry data. It need a bit experience, but nothing special. If interested in proper workflows and onsite training s then feel free to contact me on my email.
shazam

August 31, 2017 15:56
Hi, Would anyone be able to shed any light on the process on what needs to be edited within faro so that it comes in successfully within capturing reality?

I've tried taking in several geospatially referenced point clouds into faro from cloudcompare as e57 and pts formats (Merged clouds, Raw Lidar Clouds that have just been ran with one line, Clouds that have been shifted to 0,0,0) and then exported them out as ordered point clouds (ptx and e57 formats) and have had little to no luck

Is there a way I need to change the origin of the survey within faro, or am i exporting too many fields from cloudcompare?

If people require more details regarding the survey please pm

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