CS285

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CS285

• Designing Viae Globi
• (Roads on a Sphere)
• Carlo H. Séquin
• University of California, Berkeley
• Inspired by
• Brent Collins
• Gower, Missouri

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Hyperbolic Hexagon by B. Collins

• 6 saddles in a ring
• 6 holes passing through symmetry plane at 45º
• wound up 6-story
  Scherk tower
• What would happen,
• if we added more stories ?
• or introduced a twist before closing the ring ?

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Sculpture Generator, GUI
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Hyperbolic Hexagon II (wood)
Brent Collins
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Family of Symmetrical Trefoils
W2
W1
B1 B2 B3
B4
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9-story Intertwined Double Toroid
Bronze investment casting from wax original
made on 3D SystemsThermojet
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Stepwise Expansion of Horizon

• Playing with many different shapes and
• experimenting at the limit of the domain of the
  sculpture generator,
• stimulates new ideas for alternative shapes and
  generating paradigms.

Swiss Mountains
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Note
The computer becomesan amplifier /
acceleratorfor the creative process.
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Inspiration Brent Collins Pax Mundi
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Keeping up with Brent ...

• Sculpture Generator I can only do warped Scherk
  towers,not able to describe a shape like Pax
  Mundi.
• Need a more general approach !
• Use the SLIDE modeling environment(developed at
  U.C. Berkeley by J. Smith)to capture the
  paradigm of such a sculpturein a procedural
  form.
• Express it as a computer program
• Insert parameters to change salient aspects /
  features of the sculpture
• First Need to understand what is going on ?

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Sculptures by Naum Gabo

• Pathway on a sphere
• Edge of surface is like seam of tennis ball
• ? 2-period Gabo curve.

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2-period Gabo curve

• Approximation with quartic B-splinewith 8
  control points per period,but only 3 DOF are
  used.

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4-period Gabo curve

• Same construction as for as for 2-period curve

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Pax Mundi Revisited

• Can be seen as Amplitude modulated, 4-period
  Gabo curve

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SLIDE

• SLIDE Scene Language for Interactive Dynamic
  Environments
• Developed as a modular rendering pipelinefor our
  introductory graphics course.
• Primary Author Jordan Smith
• Based on OpenGL and Tcl/tk.
• Good combination of interactive 3D graphicsand
  parameterizable procedural constructs.

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SLIDE Example Klein Bottle

• Final Project CS 184, Nerius Landys Shad
  Roundy

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SLIDE Example Bugs Life

• Final Project CS 184, David Cheng and James Chow

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SLIDE as a Design Tool

• SLIDE originally a modular rendering tool.
• Later enhanced to serve as a CAD tool
• Spline curves and surfaces
• Morphing sweeps along such curves
• 3D warping module (Sederberg, Rockwood)
• Many types of subdivision surfaces
• These are key elements for a 2nd Generation
  Sculpture Generator

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SLIDE-UI for Knot Generation
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SLIDE-UI for Pax Mundi Shapes
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Via Globi 5 (Gold)
Wilmin Martono
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Via Globi 3 (Stone)
Wilmin Martono
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Viae Globi Family (Roads on a Sphere)
L2 L3 L4
L5
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Conclusions (1)

• Procedural thinking about some art object adds a
  new and promising dimension.It allows the artist
  to increase the complexity, precision, and
  optimality of a particular piece of art.
• The computer must be seen as yet another
  power-tool at the artists disposition, --
  supplementing the pneumatic chisel, the
  airbrush, and the welding machine.

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Conclusions (2)

• The computer is not only a great visualization
  and prototyping tool,
• it also is a generator for new ideas and
• an amplifier for an artists inspiration.

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Conclusions (3)

• What makes a CAD tool productive for this kind
  of work ?
• Not just virtual clay,
• partly procedural
• fewer parameters that need to be set.
• Keep things aligned, joined
• guarantee symmetry, regularity,
• watertight surfaces.
• Interactivity is crucial !

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Conclusions (4)

• Rapid prototyping (layered fabrication)must now
  be considered a new facetin the spectrum of MM
  technologies.
• It provides tangible (high-quality haptic)output
  for objects with which usersmay want to
  interact.
• Even for sculptures(intended primarily for
  visual enjoyment)the physical maquette
  disclosessubtle geometrical features that
  arenot visible in the virtual rendering.