Equilateral triangle dome

Grasshopper
1

Hi!

I have a module for an equilateral triangle that I want to use to create a geodesic dome. The dome doesn’t need to be perfect; a jagged appearance is acceptable. The same for the height, it does not need to be the same for the radius either.

I’d like to know how to construct a geodesic dome in Grasshopper with a fixed triangle size. My goal is for the triangle size to remain constant even as I change the dome’s radius. However, I realize that I can’t simply use a slider to adjust the radius, since not all values will correspond to an integer multiple of my module size. Instead, I’ve compiled a list of specific radii that work well with my triangle size.

In the code is 3 ways I have tried, but it does not give the same triangle size for all.
Equilateral triangle geodesic dome.gh (16.9 KB)

Could you guide me on how to achieve this? Thank you!

2

Hi @Sofie3,

Rhino can create an icosphere - a subdivided icosahedron.

image
image742×465 48.1 KB

test_icosphere.gh (3.2 KB)

Maybe that’s useful?

– Dale

3

When I tried your definition, I see this:

image
image608×163 3.8 KB

I’m running Rhino 7 SR37 2024-4-16. I’ve seen this a couple times recently, and not sure what the problem is / how to fix it. Any advice appreciated!

4

Hey @Bruce_Shapiro - here is a V7 version:

test_icosphere_v7.gh (3.0 KB)

– Dale

5

Thanks @dale!
But I’m also trying to understand the Python 3 Script error. Is there anything I can do on my end, short of upgrading to R8 to avoid this in the future?

6

Sorry, no.

– Dale

7

Good to know. But I also learned something. After reading your description of an icosphere and its definition, I set off to created one using components. Took me a bit, and used Lunchbox for subdivision, but it worked. Felt proud about it, until I saw that one of the standard mesh components, under Polyhedron, is “create mesh icosphere!”
test_icosphere doh.gh (13.2 KB)
:man_facepalming:

8

You can ask for the R8 Python source code and copy/paste it to the R7 Python component.

import Rhino
plane = Rhino.Geometry.Plane.WorldXY
sphere = Rhino.Geometry.Sphere(plane, radius)
a = Rhino.Geometry.Mesh.CreateIcoSphere(sphere, subdivisions)
1 Like
9

RhinoPolyhedra does provide an IcoSphere component. However, not everyone has it (nor wants it)…

– Dale