point cloud from brep ??

am asking about how to obtain a point cloud from brep to make 3d voronoi using qhull like the jpeg attached to produce 3d voronoi structure from any brep, thanks in advance :)

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drawings_01_voronoi3d-590x224.jpg, 34 KB

Replies to This Discussion

Permalink Reply by RWNB on May 21, 2011 at 10:59am

there are no points produced by a brep,
but the points are bounded by the brep.
so first create the points,
and then the required geometry (BREP).
the system requires the information of borders (BREP),
to calculate the voronoi cells
the picture which you show, (made by andrew kudless)
is also created as described.
i think so ...
http://matsysdesign.com/

look at that, is maybe better for you.
http://www.grasshopper3d.com/profiles/blogs/3d-voronoi

Permalink Reply by Ahmed Rihan on May 21, 2011 at 11:49am

Dear RWNB,

thanks alot for your reply i get it :) and the Mirjana def is very interesting and very useful for me and i have another question is how to convert from 3d voronoi produced by Mirjana def to last step in the jpeg attached, i tried to link it with the qhull 3d voronoi def but i cant, and i have another question is how to create a random point cloud in grasshopper not manually, thanks in advance :)

Attachments:

drawings_01_voronoi3d-590x224 copy.jpg, 102 KB

Permalink Reply by Pieter Segeren on May 22, 2011 at 5:11am

Hi Ahmed, to answer your last question, create a random point cloud in a Brep:
you can create random pts in its bounding box and then test how many are inside the Brep.
With Hoopsnake you can than increase the amount of random points in the bounding box and test again untill you have the desired amount of points inside the Brep. Try it.

Permalink Reply by RWNB on May 22, 2011 at 6:36am

this 3d voronoi definition comes from vincente soler.
(you don't need qhull)
you need to test it a little, to refine it.

http://www.grasshopper3d.com/forum/topics/voronoi-2?commentId=29852...

the rest you'll have to find out by yourself.
a note: http://designreform.net/2011/03/rhino-grasshopper-parametric-truss-...

Permalink Reply by Ahmed Rihan on May 24, 2011 at 8:12am

thanks alot pieter and i wanna ask what is the hoopsnake :), and RWNB your links are very useful thank you:)

Permalink Reply by RWNB on May 24, 2011 at 8:32am

http://www.grasshopper3d.com/group/hoopsnake

Permalink Reply by Ahmed Rihan on May 24, 2011 at 8:53am

thank you!

Permalink Reply by Pieter Segeren on May 24, 2011 at 9:14am

Hi Ahmed, well the thing with my hoopsnake idea wasn't working out too well, not because of hoopsnake but because when I generated N+1 random values all the points will be regenerated (differently), so I ended up with again a new amount of points inside the Brep.
Then I decided that I'd just generate a bunch of random points in the bounding box, count the number of points inside the Brep and randomly cull till I had the desired amount...

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