moving pointcloud to new position.

[blafaille]

I try to move and rotate a pointcloud to a new position.
for that i use the Translate/Rotate option.
After saving, the rotation is saved in the new las file but the position is back to the old location.
how do i save this new location too?

[daniel]

Are you sure it's exactly the same position? Because I guess the global shift will be re-applied to the cloud at export time, so the change may be 'drowned' in the global coordinates.

Or do you want maybe to drop the Global Shift and keep only the local coordinates? (in which case you can use 'Edit > Edit Global Shift & Scale' and set the Global Shift to (0, 0, 0) before saving the cloud.

[blafaille]

putting the global shift to 0,0,0 did something bit it is still not on it's place.

let me explain a little more what i am trying to do.
i have a geoslam pointcloud made in the dutch coordinate system.
Now i Also made some pointclouds with the Iphone Lidar.
These Iphone clouds are not on the proper position and rotation.

I want to relocate the iphone clouds to the right position by using the geoslam cloud as a the leading pointcloud.

So i first loaded the geoslam pointcloud as a leading cloud for the positioning and moved and rotated the Iphone clouds to the correct location.
After saving the location of the iphon cloud is back to the original location.
and if i set the global shift to 0,0,0 it is getting closer. but still not on the right location when i load the saved version of that cloud.

[daniel]

I think I understand now. The Global Shift is not transferred to the iphone cloud because you used the Translate/Rotate tool (which doesn't know that you try to register the iphone cloud with the one in the dutch CS.

Two options:
- either you manually transfer the Global Shift of the 'dutch CS' cloud to the iphone cloud (with the 'Edit > Edit Global Shift & Scale')
- or you use at least once the 'Align' tool where you pick at least 4 pairs of equivalent points in both clouds (see https://www.cloudcompare.org/doc/wiki/index.php/Align). Even if it is done very approximately, at least it will transfer automatically the Global Shift information from one cloud to the other (you'll have to choose the 'dutch CS' cloud as the reference one, and the other as the 'aligned' one).

[blafaille]

I tried both options on the Iphone cloud. but it did not work.
i also tried it on another cloud that was not made with the Iphone. and that worked great.

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[daniel]

Can you maybe share these 2 clouds with me? (admin [at] cloudcompare.org)

[kartikanur.rp]

Hi Daniel,

I also have the same problem. I have 2 point clouds. I move the first point cloud to align with the second point cloud. I already applied transformation in my point cloud and saved it as .pcd. In cloud compare, it is already aligned with the second point cloud. However, when I visualize it in open3D, the first point cloud is still in its original location (not aligned with second point cloud).

Do you have any solution for this? Thank you.

[daniel]

See https://github.com/CloudCompare/CloudCo ... ssues/2015