Grasshopper

algorithmic modeling for Rhino

# Cytoskeleton

Following on from the images I posted recently (here),

I am now making available the source script for Cytoskeleton.

First, to explain the name:

In 1903 Nikolai K Koltsov  proposed that the shape of cells was determined by a network of tubules that he termed the cytoskeleton

(the name comes from Cyto- meaning cell or hollow vessel)

This is another wireframe thickening tool, intended for 3d printing use.

In contrast to exoskeleton (which works on general line networks), this works exclusively on lines which form the edges of meshes. The additional connectivity information present in this case makes it possible to produce an output with all quads, and moreover, a quad mesh with all even valence vertices.

Because it works on a Plankton mesh, the input can be made of ngons. We can also input a triangular mesh, apply the dual operation, and then thicken the edges of the resulting polygon mesh. This works well in combination with the remeshing script I posted here, for getting approximately equal edge lengths. This can be used to quickly turn any closed mesh into a lightweight hexagonal (mostly - with a few pentagons and heptagons for curvature) frame structure.

The even valence quad mesh property of the resulting thickened mesh means we can also use the mesh direction-sorting and directional-subdivision tools from Kangaroo (described here).

When combined with Weaverbird's Catmull-Clark subdivision, this allows us to smooth the mesh, while also having control over how much 'webbing' occurs at the nodes:

from left to right we see:

• 2 levels of Catmull-Clark with no directional subdivision
• 1 level of directional subD, then 2 Catmull-Clark
• 2 levels of directional subD, then 2 Catmull-Clark

One could even combine the resulting surfaces with all sorts of relaxation, or developable strip unrolling...

The code is there for you to read, so feel free to experiment and make adjustments to it. Hopefully it is fairly self explanatory.

Please feel free to ask any questions or suggest improvements, or just show off anything you create using this.

and yes - because the input and output are both meshes, you can apply it recursively!

This script references version 0.3.0 of Plankton, which you can download here:

https://github.com/Dan-Piker/Plankton/releases/tag/v0.3.0

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Make sure the Plankton .dll is not blocked in C:\Users\........\AppData\Roaming\Grasshopper

omg! my mind is sploded :O

Hi everybody, could you advise where I can find cytoskeleton node in Grasshopper?

by June Lee

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