Level by using walls

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prwurech
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Joined: Thu Aug 31, 2017 12:55 pm

Level by using walls

Post by prwurech »

Hello cloudists!

I am using point cloud data from a terrestrial scanner that hasn't been leveled correctly:

the cloud need to be reoriented without using the level tool, since all horizontal planes tend to have 1°+ inclination for the rain drainage.

Is there a way to use the "fit plane" function on vertical walls to reorient the cloud?

Many thanks for advises!!!

phil
daniel
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Re: Level by using walls

Post by daniel »

Not sure.

You could use the 'fit plane' tool to fit a plane on your wall (or a part of it if you segment it first). And then you can 'edit' this plane (right click on it or use the new 'Edit > Plane > Edit' tool (you'll need the latest 2.9 beta version to do this). You can see the 'dip' and 'dip direction' values of this plane (it's a geological convention, but you can find some understandable documentation about it on the Internet). I guess in your case you'll want to change the 'dip' to something like 89 degrees.

From there you could change the plane 'dip' value directly in the 'edit' dialog, but it will only change the orientation of the plane, not the cloud... we should output the reorientation matrix in the Console for you to use it. However this is not done acutally.

Meanwhile you may be able to guess the right rotation to apply to the cloud (with 'Edit > Apply transformation') by considering how much 'dip' you want to add or remove to the current value (and making the wall aligned with X or Y so as to rotate about one of these axes). Anyway it will represent some intensive tinkering...
Daniel, CloudCompare admin
daniel
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Re: Level by using walls

Post by daniel »

EDIT: I just updated the latest online 2.9 beta release.

I fixed a bug in the 'Plane edit' dialog, and it now outputs the transformation matrix when you change the dip value of the plane. This way you can simply copy it and use it on the cloud with 'Edit > Apply transformation'.
Daniel, CloudCompare admin
prwurech
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Joined: Thu Aug 31, 2017 12:55 pm

Re: Level by using walls

Post by prwurech »

Merci Daniel! The trick works like a charm. I combined screenshots to make it fast to understand for other users:
level-with-2-facades.jpg
level-with-2-facades.jpg (118.51 KiB) Viewed 1166 times
daniel
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Re: Level by using walls

Post by daniel »

Thanks for the image. I'll add it to the wiki documentation of the level tool.
Daniel, CloudCompare admin
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