IF (this is not the direction I need to go)……

THEN ( I don’t know what) ELSE (I should be doing).

Anybody got a good resource on syntax & creating if, then, else operations? I’m thinking I need one to tell grasshopper not to create any band that goes around a corner (possibly where the points are not on the same plane or where they are further apart than a set distance, because it will result in a warped loft). Any links on making a conditional function or any ideas on a better way to preclude these instances?

Cappellini Wooden Chair (Marc Newson by Merav Lahr)

For the parametric seating assignment, I choose to work with Marc Newson’s wooden chair for Cappellini.

cappellini wooden chair image slide

The chair is made of 3 parts: a curved, triangular base; 4 curved rectangular frames; and, 20 ribs, each a different size.


In Rhino, I drew the curved line for each piece of ribbing and swept a rectangle along it. For the frame, I used arcs and rectangles along with the sweep tool; for the base, arcs and triangles with the sweep tool. Below are 4 views of my model (clockwise from top left: front elevation, left elevation, plan view, perspective):

rhino model slide

For the second half the assignment, I will use Grasshopper to explore the following design drivers:


back height diagram


rib width diagram


seat shape diagram

Alex Smith Bench Project

Full Bench ASJS_bench_ribsASJS_bench_skin

Possible design parameters for extension or manipulation in grasshopper.

  1. Input curve – The bench could be generated on any curve
  2. Number of ribs – or possibly density of ribs
  3. Number of spines – or density of spines
  4. Thickness of spines
  5. Seat back height at highest point
  6. Seat depth at deepest point
  7. Distance from end A to beginning of transition to seat
  8. Distance from end B to beginning of transition to seat