Sand dune/Medial Axis (SAMPLE)

Here is a script replicating the shape created by pouring sand on a closed shape (here a polygon). From above it draws medial axis, but here it is a Brep generated from a closed polyline. The limit angle of repose is here 45° but it could certainly be changed by using a scale in Z.

The script use just classic Rhino/Grasshopper function. It didn't work with all polygons, I didn't search why. The closed polygon must be on XY plane, it could be clockwise or anti-clockwise.

Have fun, me I will continue to play with real sand on the beach for some days :-)

Attachments:

Sand_dune_medial_axis_closed_polygon.gh, 33 KB

Replies to This Discussion

Permalink Reply by djordje on December 30, 2017 at 11:32am

This is great!!!
Thank you Laurent!!

Permalink Reply by Aleks on February 5, 2020 at 4:05pm

What do you think about this idea?

Permalink Reply by rebecca on October 20, 2016 at 2:56pm

Hello!

I am trying to extract the interior volume as an object instead of the negative of a Boolean operation.

Is it possible to pour the sand into this volume?

Attachments:

Please Help Me.3dm, 1.1 MB

Permalink Reply by Laurent DELRIEU on October 22, 2016 at 12:48am

I didn't look to your file but at the moment I can just propose you
http://www.grasshopper3d.com/profiles/blogs/veinization?xg_source=a...
To calculate a sort of medial axis of a volume. But it is curve not volume. But as you write at all discussions of medial axis I suppose you want medial axis for 3D shape. But I think medial axis for 3D must be surfaces because on 2D you can make the shape with medial axis ans disc. In 3D you can make the shapes with placing spheres on surfaces.
You can search also on skeleton for mesh
http://visgraph.cse.ust.hk/projects/skeleton/
http://doc.cgal.org/latest/Surface_mesh_skeletonization/index.html

Permalink Reply by valentina Lucich on February 5, 2020 at 3:27am