Aligning point clouds with sunset cloud

[Zhilgy92]

Hello! I am relatively new to CC, but have used it on and off for examining point clouds for a number of years. I am trying to figure out if there's a way for me to extract a subset of points to run the fine registration/ICP tool on, that affects the whole cloud. Basically, I have a number of point clouds that are from the exact same place over an extended period of time. Certain features, like the tops of buildings, have not changed. The rest of the surface is and active sand plain and changes regularly. I would like to use the tops of the buildings, only, to align the clouds because I know their position has remained unchanged during data collection. The Segregation tool seems to remove the selected points from the original cloud even though it can isolate the rooftops. The Point-to-point tool also doesn't seem right, because I want to use all of the points in the rooftops to align the clouds, not just a course hand grab. Any help would be greatly appreciated! Thank you for your time!

[daniel]

Can you more simply manually segment the clouds with the scissors or the Cross Section tools? (you can do it all at once by selecting multiple clouds).

Then you can use the cropped parts for registration. You'll see the resulting registration matrix appear in the console. Copy-paste this matrix and apply it to the original cloud with the 'Edit > Apply transformation' tool.

[Zhilgy92]

Daniel, thank you for the response! Apologies for the multiple typos...

I didn't even think about that approach, but it makes perfect sense! I'll give that a shot. Thank you for the help and timely response!