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intersects

Posted: Sun Sep 07, 2014 3:20 pm
by hairyfreak
Hi, i'm very new to cloud compare, so please forgive me if this is an obvious question, i've been scurrying around lots of different softwares to find and answer but to no avail at the moment.

Is it possible split 2 (or more) clouds/meshes into segments along the lines of intersect?
I'm after making a positive of the space between intersecting meshes, and removing any extra bits beyond the intersect lines.

Cheers,
-A

Re: intersects

Posted: Mon Sep 08, 2014 7:47 am
by daniel
If I understand well, what you need is a CSG-capable software (what is also called 'Boolean operations').

For meshes, there must be some solutions around. CloudCompare doesn't have any CSG capability yet (we plan to integrate the Cork library - https://github.com/gilbo/cork - but not right now). And for clouds I've never heard of such an algorithm (I bet it's easier to mesh the clouds first).

Daniel

Re: intersects

Posted: Mon Sep 08, 2014 11:36 am
by hairyfreak
Hi, thanks for the reply, I'll keep looking and if I find a solution i'll try and remember to come back and post for anyone else interested.
Cheers
-
aP

Re: intersects

Posted: Thu Oct 02, 2014 8:22 pm
by daniel
For the records, CC has now a CSG-capable plugin based on the Cork library:
http://www.cloudcompare.org/doc/wiki/in ... PluginCork

The latest relese version (2.6.0) now incorporates this plugin.

Re: intersects

Posted: Tue Dec 02, 2014 10:27 pm
by hairyfreak
Hi,

Thank you very much for getting back. I've finally got back round to looking at this again and found an effective solution with the existing tools.

Embarrassingly simple and I expect it's just that I didn't word my question clearly, but for anyone else stumbling like me, here's the current solution. Will update when try it out with more complex scenarios

• import 2 "surfaces" (as point clouds, using polygon models didn't work for me) NB. Must have vertex normals
• do distance comparison, and select-out all points of close match
•repeat for both surfaces
•flip normals on 'bottom' surface
•combine
• mesh.

does the trick for now.

For more complex intersecting shapes I think I may need then boolean operations and have a few ideas that I don't know if are reasonable or now., but will let you know as I go.

I'm having a few issues with files over 10MB though (as ply), but this may be me missing something obvious and will look into this separately when I get chance.

Thanks.