Voronoi 3d - selecting only facade curves

Hi.
I am using a Voronoi script that creates cells inside a simple volume. So I have got a lot of cells consisting of faces. Now I want to select only the faces on the four facades and not those in the middle of the volume. (see attached).
Does anyone know how to do this? Maybe something about finding curves on a surface or something?

Thanks Rasmus

Attachments:

Voronoi.jpg, 305 KB

Replies to This Discussion

Permalink Reply by Rasmus Holst on November 19, 2009 at 6:49am

well I have as many normals pr cell as there are surfaces pr. cell.

Permalink Reply by Thomas Bildsøe on November 19, 2009 at 6:54am

Ok, but what about the lines being infinite?

Could you post the definition?

The last step is creating the cull-list. I found a solution but it aint pretty.

You take the resulting intersection points, put them through a formula component using just x.x as expression. This will yield null values for normal lines which didn't intersect. Next you use the Null component, use it as pattern for cull pattern and invert it, and input your cell surfaces as input list.

But it will only work if your datatrees matches.

Permalink Reply by Rasmus Holst on November 19, 2009 at 7:00am

Now I tried using the 4 BRep surfaces as BRep in the intersection. The lines do not seem to be infinite, but the intersection points output, are not where the normals should intersect.

Attachments:

Voronoi3d 2 upload.ghx, 508 KB

Permalink Reply by Thomas Bildsøe on November 19, 2009 at 7:13am

Perhaps also the 3dm!! :)

Permalink Reply by Rasmus Holst on November 19, 2009 at 7:16am

You're right :). Only a plane for the extrude box and some points.

Attachments:

Voronoi 2 upload.3dm, 47 KB

Permalink Reply by Rasmus Holst on November 19, 2009 at 7:34am

If I try to make the intersection with only one basic volume surface it seems to work.

Permalink Reply by Thomas Bildsøe on November 19, 2009 at 8:18am

Yep, the brep consists of several faces so that might lead to errors.

Btw. the solution i mentioned earlier dosn't quite work only sometimes. The formula component doesn't allwyas return the correct number of values. So i'm afraight that for the whole simple volume some scripting is needed.

Permalink Reply by Rasmus Holst on November 19, 2009 at 9:19am

I quess you're right. Now I will have to take it one surface at a time, to get on with my project. The deadline is closing...Thank you very much for your help, if you decide to make a script or get some other ideas, please let me know... I will do the same.

Rasmus

Permalink Reply by Psymila on June 6, 2010 at 11:58am

Hey, I was wondering if you could share the Vornoi script that lets you do that. I've been trying for a while now to get some results like those in the attachment, so I can have several volumes made from a single voronoi. Can you help me?, thanks a lot.

Attachments: