Comparison of point clouds - revit + dynamo

Hi Everyone,

I haven’t started building a script for this yet, I’m just testing the waters to see if it is even possible and what direction I should be heading :-

We’ve taken 2 laser scans of a large steel chilled water tank over a period of around three months, we’re looking to assess if there is any differential movement in the walls of the tank between the two scans. At the moment, I load both scans into Revit, then cut around 15 sections at various locations around the tank walls and compare the points in section to see if there is any change. It’s long and it’s tedious.

I was hoping that I might be able to create 2 surfaces from the point clouds, I’ve done some reading about some of the nurbssurface nodes and that looks to be the go - pull the points into a surface, and then do a volume calculation or subtraction or something between the two surfaces to get the net difference? What does everyone think?

I wouldn’t even try. Trying to rationalize even a tiny point cloud would completely choke Revit & Dynamo. You’re better off converting the PC to a mesh and importing the result with the Mesh Toolkit:

https://www.youtube.com/results?search_query=meshlab+pointcloud+to+mesh

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@rad1cal
try Cloudcompare
http://www.danielgm.net/cc/

It is a brilliant open source application for working with pointclouds and can calculate differences between scans, as well as creating meshes or poly lines

As it turns out, one of the examples on the CC website is of a large tank:


I agree with Dimitar- Dynamo just isn’t cut out for this kind of task

Andrew

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Hmmm, that’s disappointing - but I was kinda thinking I might be barking up the wrong tree…
Thanks very much Dimitar & Andrew, I’ll check out the leads you posted and report back.