Smothed outer surface from a 3D set of points


(Gustv Asc) #1

Hello guys,

Is there any way to find the outer surface of a point cloud in Grasshopper? I´ve been working with robotic manipulators and would like to find a nice way of representing workspaces as a closed surfaces, so that one could make sections and analyse them as wished.

Until now, I have been creating spheres centered in those points (via Grasshopper) and working with multiple intersection planes to draw (manually) a rough outer surface from curves in different levels. :sweat_smile:

I would be happy to find a smarter way of accomplishing this task.

Thanks a lot! (3.8 KB)

(Laurent Delrieu) #2

Alpha shape 3d ?
And no data in your file !!!

(Gustv Asc) #3

Sorry. Laurent. I thought I had successfully internalised the .txt data to the .gh file. In any case, I send it attached.

Thanks for the tip about the Alpha shape! I am trying to learn it.

Workspace.txt (200.9 KB)

(Laurent Delrieu) #4

Here the script with Alpha Shape 3d

There are some holes but you have a mesh. Parallel version of Alpha Shape is faster.
point cloud alpha (13.5 KB)
There are windows !! I dn’t know if it is my script or Delaunay 3d (from Mesh Edit)

Volume from points in 3D Space (problem with invalid mesh)
(Laurent Delrieu) #5

And with some random move on Z the mesh is closed

point cloud alpha (12.7 KB)

Generate solid from points
(Gustv Asc) #6


That´s amazing! I really appreciate what you did here. Thanks! This helps me a lot!


(Pfotiad0) #7

Good stuff. BTW: I would suggest some auto calculate ability for the radius. Shown an internal BPA thingy for LIDAR pts and the likes.