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SIGGRAPH 2004, OZONE. Turning a Snowball Inside Out: Mathematical Visualization at the 12-foot Scale. Alex Kozlowski & Carlo H. Séquin: U.C. Berkeley Dan Schwalbe: ComSquared Systems, Eagan, MN Stan Wagon: Macalester College, St. Paul, MN John M. Sullivan, Tech. University, Berlin.
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SIGGRAPH 2004, OZONE Turning a Snowball Inside Out: Mathematical Visualization at the 12-foot Scale Alex Kozlowski & Carlo H. Séquin: U.C. Berkeley Dan Schwalbe: ComSquared Systems, Eagan, MN Stan Wagon: Macalester College, St. Paul, MN John M. Sullivan, Tech. University, Berlin
“Whirled White Web” 3D-Print
Day 1: The “Monolith” Cut away prisms …
End of Day 2 The Torus
The Winners 1st: Canada – B.C., 2nd: USA – Minnesota, 3rd: USA – Breckenridge “… sacred geometry … very intricate … very 21st century !”
What Are We Going To Do For 2004 ? “Turning a Snowball Inside Out” Making a Model of the Half-way Pointof the Sphere Eversion Process
Sphere Eversion is Possible ! PINCH • First proven by Steve Smale around 1960from complex topological arguments. • But he could not say HOW it can be done … ! • Surface may pass through itself, • but no ripping, puncturing, creasing allowed,e.g., this is not an acceptable solution:
Sphere Eversion Process • A few years later Bernard Morin, a blind mathematician, figured out how to do it. • In his honor, the half-way point,where half each of the inside and outside of the sphere shell can be seen, is called the Morin surface.
Sphere Eversion Process • You need a rather contorted move to achieve the desired goal. • Bernard Morin figured out one such path. • Charles Pugh made models from chicken wire. • Nelson Max made a first computer simulation.
Optimal Sphere Eversion • In the 1990’s John Sullivan found the most efficient way (using the least surface bending)to accomplish this eversion,and made a beautiful movie of it. From: John Sullivan: “The Optiverse”
The Simplest Polyhedral Model Partial cardboard model based on cuboctahedron eversion by Apéry & Denner.
Shape Adaption for Snow Sculpture Restructured Morin surface to fit block size: (10’ x 10’ x 12’)
Make Surface “Transparent” • Realize surface as a grid. • Draw a mesh of smooth lines onto the surface …
Gridded Models for Transparency SLIDE virtual model 3D-Print from Zcorp
“Turning a Snowball Inside-Out” Carlo H. Séquin, Alex Kozlowski, John Sullivan Dan Schwalbe, Stan Wagon
Day 1 Day 1
Day 2 A Template for the “ear”
Day 5 End of Day 4