Modeling Perforated Spheres with Controlled Hole Spacing in Grasshopper

[Brian_A_Tseng-Nicode (Brian A Tseng-Nicodemus)]

Hi Everyone,

I’m a beginner in Grasshopper and am trying to figure out how to model a coral-like sphere for 3D printing, similar to the one in the first image below. I’ve been using ChatGPT for guidance, but I’m feeling a bit stuck and hoping to get clarification here on the best approach to build the definition properly.

What I’d like to create is a sphere with:

• A flexible number of holes (I’d like to control this as a parameter),
• Varying hole sizes (randomized, but within a controlled range),
• And minimum spacing between holes so they don’t overlap.

I’ve attached some reference image to show what I’m aiming for, and the definition I put togetehr so far. Could anyone please help me with tips, guidance, or examples on how to approach this in Grasshopper?

Thank you so much for your time and help!

[martinsiegrist]

There are a few examples on this forum. Look for circle packing…

Here’s one:

Golf ball? Evenly spaced points on a sphere?

Here’s a circle packing on a sphere in the current Kangaroo: circles_on_sphere.gh (9.9 KB) [image] It’s still not clear to me exactly what you are after though. Is this literally for a rendering of a golf ball? or you want to actually make a golf ball? or is it a more general question for some other application, and if so what? If the requirement is to have a distribution of points (or dimple centres) on a sphere, all at exactly the same distance from their neighbours, then this is only po…

And another nice video by @danielpiker:

[Joseph_Oster]

@Brian_A_Tseng-Nicode wants an assortment of sizes, eh? The circles on the golf ball were all the same size.

https://discourse.mcneel.com/search?q=circle%20packing%20various%20sizes

Compact circle packing on complex surface

Here’s a version that allows multiple boundary curves as input [image] compactcircles_multiboundary.gh (18.9 KB) Note that while there always exists a compact circle packing for a given connectivity graph within a single boundary curve, this is no longer true for multiple boundaries, so the circles generally cannot all be perfectly tangent.

[laurent_delrieu]

Hello
you can generate spheres holes using this script

Circle packing with fixed radius and fixed number of circle for each radius

It looks like in that image they’ve used a compact circle packing (each gap between the circles has 3 sides) In general this will mean the circles are all of slightly different sizes. You can pack circles of predefined sizes on a surface with the definitions I posted above, just adding an OnMesh goal with your target surface, but it won’t be as neat - many of the spaces between the circles will have 4 or more sides. Here’s an example for a compact circle packing on a surface: CompactCirclePa…

In order to have initial points, generate a convex hull with random point at the surface of the sphere. You can use Populate Geometry then Convex Hull (not sure it is on Rhino 7 but there are others tools for convex hull)

Or a less good tool (Populate Randomly from Nautilus), as it is more random spheres will have more different radiuses.

Then make all the circles/spheres a little smaller, then cut the sphere with sphere and a base.
CompactCirclePackingOnSurfaceAnd Cut Sphere.gh (30.7 KB)

Nautilus plugin not mandatory.