# Geodesic Dome - Nodes problem

Hi everyone!

I am trying to make a geodesic dome with hexagonal or pentagonal structural nodes (depending on the position) The idea is to do it this way.

First I did it with the Polygon component but the Hexagon lines were not perpendicular with the dome bars, then I did it with lines, with the End Points component, so that when they intersect I can extrude them, but the problem is the planes of the curves because they are not consistent.

Geodesic dome - Nodes problem.gh (51.8 KB)

I’m approaching the problem wrong, does anyone have any idea how to solve it?

Thank you in advance!

PS: I was able to make one node, but the idea is to make all of them at the same time.

Geodesic dome - Nodes problem Edited V0.gh (25.0 KB)
Plugin: Parakeet

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For Domes you’ll need to get the gist of the theory first (base seed Topo, frequency etc etc). Then … do the Dome as a Mesh where VV, VE, EV Connectivity (and obviously various things like order of TopologyVertices per node) is a rather easy thing to handle. Then use Instance Definitions if the nodes are many (and the detail required is more or less decent) otherwise … you can imagine what would happen.

Tip: use some MERO TSK system (the worldwide standard: kinda a BMW M3). Have in mind that a W truss (say via the KK node variation) is always “lighter” in the eye for more than obvious reasons (there’s carbon fibre tubes available as well that yield stunning aesthetics).

https://www.mero.de/en/construction-systems/nodesx/nodes.html

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This is incredible! It wasn’t going to occur to me, thanks for the help! @Quan_Li

Thanks for the link, I’m going to read to understand the subject better!

Tips:

1. Google geo domes geometry and the likes. Zillions of papers available. Like:
geodesicmath.pdf (651.1 KB)
2. Master Mesh Connectivity (in this case you’ll need VV, VE and EV Trees). Any AEC solution without Connectivity is a nothing thing. That said the more the Dome deviates from a Sphere (i.e. Transformation in x/y/z) the more the Modules grow in variety (but that’s not an issue at all except if you are after some toy-model).
3. Avoid Class II Domes (rather kitsch).
4. As I said if you are after a “sparse” structural Topology go for a double Layer (i.e. a W truss).Shown a variable D solution (D is relative to dist to base).

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Tips:

1. The Class is the way that triangulation is made (go for the classic Class I way).
2. The Frequency is the “depth” of triangulation.
3. The Seed/Base is some Platonic (or other) Topology as a Mesh. in order to handle easily Connectivity and the likes. Plus since Meshes are using floats are always faster than, say, BrepFaces/Surfaces.

Then:

For each Triangle in the seed Mesh > triangulate > “project” node. For the latter define a Vector3d V as node - centerOfSphere. Then Unitize. Then multiply by R - node.DistanceTo(centerOfSphere). The “projected” pt is node + V.

Elementary via code. See a concept C# for that matter:

Is that easy? Well … in fact in real-life/real-world we gather (at triangulation Phase) the “identical” Faces into “groups” using Properties in a suitably defined Class. This for production/BID purposes (for large scale Projects these groups have no impact to the cost - it’s just a matter of dihedral angles in the alu extrusions related with the envelope).

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