How to Make the kanga-pipe Object


Perfect Version (Somewhat Tedious)

  1. In Grasshopper, make a Mesh Box using the default parameter values. This will give a mesh with 10 x 10 faces per side.
  2. Scale the box by 25%.
  3. Move the box by 2.5 along all three axes, so one corner is at the origin.
  4. Bake the box.
  5. In Rhino, turn on Grid Snap.
  6. Make copies of the box in Rhino and position them to create the pipe shape.
  7. In Rhino, do Boolean Union on all the boxes to create a single mesh.
  8. Open up the ends of the pipe by selecting and deleting individual faces or edges with control-shift-click (command-shift-click on the Mac). This is the tedious part.
  9. Save the file as kanga-pipe.3dm.

Quick and Dirty Version (Some Imperfections)

  1. In Rhino, make a Solid Box. This box will have one face per side.
  2. Make copies of the box and position them to create the pipe shape.
  3. Combine the boxes with Boolean Union.
  4. Open up the ends of the pipe by selecting and deleting individual faces with control-shift-click (command-shift-click on the Mac).
  5. Use the _Mesh command to convert the poly-surface to a mesh. Click on the Details button and set the Max Edge Length to 1. Also turn off Jagged Edges. This produces a mesh that is a mix of quads and triangles. The result is sloppier than the previous version, but this approach is more general and faster.
  6. Note: Rhino 7 has a QuadMesh command that might do a better job.
  7. Save the file as kanga-pipe.3dm.
  8. When you import this mesh into Grasshopper, run it through Weaverbird's Join Meshes and Weld component, and set the W (weld) parameter to True. This will eliminate false naked edges.
Dave Touretzky