This is an exploration of the geometric basis of sculptor Richard Serra's Torqued Ellipse IV (1998). Torqued Ellipse IV, constructed of 2-inch-thick weathering steel, is about 12 feet high on an elliptical footprint with 33 and 22 foot axes. Its "skylight" opening is an identical ellipse, rotated an angle of 90 degrees. The shell is generated by a line that connects the tangent points, lower and upper, of a plane rolling on the ellipses. This sculpture was most recently installed at the Museum of Modern Art in New York.
The model opens using Torqued Ellipse IV's proportions, and the model can be reset by clicking on the "+" in the upper right and selecting "Initial Settings". Think you can improve on Serra's proportions? You can change the geometry by using the Geometry sliders, and the visual effects using the segment buttons.