A little behind the screen action from West Coast Timber engineer, Even Clow, of this conical roof structure for a pavilion in North Carolina. It reminds us of Spirographs from when we we kids, and is equally as fun and challenging to design today in this real-world application. "The spirograph is created from the series of ellipses that describe the top surfaces of the blocking that flush them out to the surface of the cone." -- Evan