Exported Point Clouds Not lining Up

PIX4Dmapper
1

Hi All,

We use TBC (trimble business centre) to ‘clean up’ the export point clouds from Pix4D, as you’re all well aware Pix4D breaks the point cloud down to multiple clouds (I assume it’s easier for the software to process it) however, when checking in TBC the clouds don’t line up perfectly and are circa 1.5m apart. All alignment of the photos, GCPs etc while processing in Pix4D didn’t throw up and errors, so I don’t believe it’s anything to with the processing of the data, just potentially the export.

I though this could be to do with projections/ co-ordinate systems in TBC, but this wouldn’t cause a 1.5m change in position and importing all the laz files at the same time would by rights make the all datasets relative together thus error error in TBC = dataset all out by the same amount. Which leads me to the export from Pix4D.
That’s my thought process anyway, I’m open to being corrected.

Any assistance/ advice with this would be welcomed as It’s bugging me.

Image 1
Image 11691×809 467 KB

2

Hi Chris,

Could you please send us the following?

▸ The quality report (.pdf format): …\project_name\1_initial\report\project_name_report.pdf
▸ The project log file (text file): …\project_name\project_name.log
▸ The project file (.p4d): …\project_name.p4d
▸ The pointclouds

May I also ask where did you try to import the pointclouds and you noticed this difference? Can you send us a screenshot of the raycloud?
Have in mind that if you want to create one file only that contains the pointcloud you can enable the Merge Tiles into One File option as shown below:

2021-11-23_15h59_14
2021-11-23_15h59_14788×738 74.7 KB
.

I hope this helps.

Best,

3

Hello, I had the same issue. Pix4D generated 4 point cloud .las file for me, and when I would import them into TBC they would each have a significant “gap” between them.

This post on Reddit got it working for me.

Here’s the answer in Reddit that worked:
“If your point cloud is already geolocated, when you import it select ‘point cloud from unknown source’ with ‘unknown coordinate system’. TBC will then not shift its position.”