Hi,
I would like to create a mesh from a point cloud with the DELAUNEY MESH component in GH. It works fine for 90% of the point cloud but occasionally it creates these strange faces.The plane parameter of the DALAUNEY MESH component seems to have an affect. How can I avoid these strange faces?
POINTCLOUD.3dm (11.3 MB)
Delauney works for co-planar (or almost co-planar) collections. For anything else use some BallPivot algo (I’m sure that some time ago someone provided a C# and/or a compiled component that does BP stuff [had a bug or two, mind]… but I can’t recall the name(s) nor the thread).
There’s also another way (get your points in Plane.WorldXY do the Del mesh on that planar collection and then “remap” the vertices back to the OEM ones … but that works for sheet like topologies with non negative slope)
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Thanks a lot. Unfortunately I can’t download the GH definition by David Reeves anymore. Found this link https://www.grasshopper3d.com/photo/ball-pivoting-01?test-locale=&exposeKeys=&xg_pw=&xgsi=&id=2985220%3APhoto%3A954968&groupId=&groupUrl=&xgi=&page=1#comments.
The second option doesn’t work for me since the topology has negative slopes.
Yes that was the name (David Reeves). Now I remember that I’ve tested that one (I have my own stuff for that matter) and found a glitz in the glue Method that occasionally does bad things. And this is the BP thread from the good old dead Forum (for some reason I can’t copy paste the link, so go there and search: BallPivot):
But I can download the gha
BallPivot.gha (14.5 KB)
That said I remember that the thing should provide an option for auto finding some search R: say by measuring all pt-pt distances (takes a bit of time if you have some zillions around) and then getting the max x some user value (if <1 then you should get Lists of meshes).
Have in mind that the OEM Ball Pivot (by the notorious IBM Labs) had issues with non “uniform” pt collections. Not sure what type of stuff David adopted for his thingy. These days a lot of improvements are done (most notably using // ) and this is no more an issue. The new generation is used first in the Tomahawk cruise missiles.
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Awesome! It works! Thanks a lot!
Realized that Meshedit has a 3D Delauney integrated: https://www.food4rhino.com/app/meshedit
Alternatively the Rhino command Meshfrompoints does a great job as well: https://www.rhino3d.com/download/rhino/5.0/meshfrompointsV5x64
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Yes, Meshfrom points does a clean job, however it is not precise.
