Grasshopper

algorithmic modeling for Rhino

# Control Distribution of Points within Boundary

I'm looking for a way to create an uneven distribution of points within a boundary. In this case the boundary is a triangle. I want more points toward the corners of the triangle and fewer points toward the center.

Even though the density of the points will vary throughout the area within the triangle, I'm looking for a nice and even transition between the dense corner areas and the sparse central area.

I have made several unsuccessful attempts at this, where the logic involves offsetting the points of a uniform grid using an attractor point. However, one of the problems with that approach, is that the points towards the edges get pushed beyond the boundary. I need the points to stay within the boundary at all times.

Thanks everybody

Views: 2224

### Replies to This Discussion

Do you want it to be a regular or irregular distribution?

For irregular put some points inside the triangle with pop3d. Then use the corners as attractor points to displace the points towards the closest corner.

Hi Hannes -- your method works well, thanks for the tip.

-Bret

Regular seems to be the hard part. How to do it regular then, like this?

yes, that is awesome.

I'm sure Daniel (I think Daniel Piker made that original image) did something incredibly clever to get that result. Here's a way to kinda sorta get the same result:

--

David Rutten

david@mcneel.com

Attachments:

Thanks. That's kind of eccentric. Let's see...it relies on mesh relaxation and its ability to skip naked vertices, meaning the outside ones. It starts by dividing a border curve into points, also fills the interior with points, and then...uh...I'll study it further later. It's not as regular (nearly equilateral) as I imagine is possible, perhaps using physical forces so the points repel each other with there force being determined by distance from the boundary.

What I'm also interested in eventually is that this could be converted into a relief that amounts to the sort of puffing that Delcam Artcam or RhinoEmboss does so well, by adding Z value heights to each point according to the area of of mesh faces around each point or the length of lines around them.

Very cool. Thanks for sharing Daniel. Can't wait to try it out.

YOU DID IT!!! This is perfect. Just perfect. My bit of nagging paid off. Big time. With this I can really start playing with meshes that aren't so damn ugly or overly uniform, both artistically and mathematically. Though I don't here have the option of setting a specific fall off curve of size versus distance, I can do that with height values myself, based on inputting the circle or face area and rescaling unevenly as I desire.

Thanks!! this is very VERY useful...

by Anna

by Anna

by Anna

• View All