Wednesday, 1 September 2010

Grasshopper Curve Force Density (Great Court Roof Revisited)

First thing to state, I plan to revisit the topology (connectivity) of the curve network to get a better result, so please come back soon and check if it's updated.

I've been adding curve network force density tools into the Grasshopper BullAnt plug-in.  There's progress on using the Great Court Roof as an example.

You can download the Rhino file here and the Grasshopper definition here.

Also possibly of interest is a "reverse" force density where it iterates through the network nodes and repels the neighbouring nodes rather that move the current node, which can be used in some circumstances to produce equal length curves.  Here's one example, although it seems there's lots of scenarios where it's not so successful. I've put a slider on the iteration so you can see it converge on an answer, and it's producing two adjacent loop results so you can compare.

Rhino file here and Grasshopper file here.


  1. Hi
    Can I ask which version of Grasshopper these defenitions are write in, I tried 060059, 070057 and also 080001 but I had error messages with them.
    Maryam Mirsoltani

  2. Hi Maryam,

    It was generated in GH v0.7.0047 but can be opened in the newest.

    If you have StructDrawRhino installed ( ) but not GH Icons, then please start rhino, start Grasshopper, and then run the rhino command GrasshopperDeveloperSettings and untick COFF loading. Restart Rhino. Note you should also run the rhino command sdrZZLicenseRequest and follow the prompts.



  3. If you are carrying out a structural analysis, then you should note that in the British Museum roof there is no out-of-plane restraint from the outer perimeter (to avoid putting out-of-plane loads on the brick/stone facades). The central ring is supported by a new steel structure and therefore provides restraint in all directions, although not perfectly stiff, of course.