how to cull off the edge points of the grid?

I have a surface which is divided into a grid. But how can i erase the points of the 4 edges?

thanks a lot.

Replies to This Discussion

Permalink Reply by Mitch Heynick on March 14, 2010 at 9:46am

Well, since nobody answered yet... attached is a rather complicated definition (I'm sure there's a simpler way) with two possibilities - 1) cull just the corner points and 2) cull all the 4 edge point sets. FWIW... --Mitch

Attachments:

UVCull.ghx, 182 KB
CullEdgePts.PNG, 100 KB

Permalink Reply by David Rutten on March 14, 2010 at 9:58am

Another solution would be to duplicate the surface edges, measure the distance from each point to the closest edge (Pull component), and if that distance is very small, we assume the point is on the edge. So create a culling pattern from the distance (route it through a Larger Than component).

--
David Rutten
david@mcneel.com
Poprad, Slovakia

Permalink Reply by Damien Alomar on March 14, 2010 at 10:05am

I answered in another thread.... Little less complicated than yours, but not as simple as David's, although I think the pulling operation could be somewhat "heavy" if its on a surface with a lot divisions (or multiple surfaces)...

http://www.grasshopper3d.com/forum/topics/help-geometry-orientation...

Permalink Reply by David Rutten on March 14, 2010 at 10:08am

Absolutely, my solution is a lot slower than directly generating culling patterns. It is however pretty flexible in that it isn't limited to just edge curves (any geometry will do).

--
David Rutten
david@mcneel.com
Poprad, Slovakia

Permalink Reply by Mitch Heynick on March 14, 2010 at 5:05pm

Hey Damien,

That is quite an interesting solution... I had tried doing it with trees, I got to the halfway point in your solution (easy, as the points are stacked in columns along V), but I couldn't figure out how to path the U stuff...

I didn't realize it was possible to do string concatenation in the f(x) component (well, there's a lot of things I don't know)... Looks like that opens up some interesting possibilities... --Mitch

Permalink Reply by Vicente Soler on March 14, 2010 at 11:32am

Usually when people ask for removing the points in the edges, what they really want is the center of the imaginary cells that would be generated when subdividing a surface. The Divide Surface component gets the corner points of these imaginary cells: