ZUERICH, July 4, ZUERICH, July 4, 20122012

Shape Realization

Carlo H. Séquin

University of California, Berkeley

CITRIS Building Startup Space Committees Plenary2

Center for Information Technology Research in the Interest of Society

CITRIS Building Startup Space Committees Plenary3

A few typical spaces . . .Small conference roomSmall conference room Signature conference roomSignature conference room

(sixth floor)(sixth floor)

Entrance to main auditoriumEntrance to main auditoriumEntrance corridorEntrance corridor

CITRIS Building Startup Space Committees Plenary4

Main Auditorium (third floor)

CITRIS: Digging a HoleCITRIS: Digging a Hole

Pouring the Mud SlabPouring the Mud Slab

Wall Construction: ReBarWall Construction: ReBar

Steel Frame RisingSteel Frame Rising

Fearless Steel WorkersFearless Steel Workers

Facade Going UpFacade Going Up

Building Almost CompleteBuilding Almost Complete

Complex Work on the InteriorComplex Work on the Interior

Brent CollinsBrent Collins’’ ““Pax MundiPax Mundi””

1997: wood, 301997: wood, 30””diam.diam.

2006: Commission from H&R Block, Kansas Cityto make a 70”diameter version in bronze.

My task: to define the master geometry.

Target GeometryTarget Geometry

Constraints:• Bronze; 70” diameter• Less than 1500 pounds• Less than $50’000• Maintain beauty, strength• Minimize master geometry

SLIDE-GUI for SLIDE-GUI for ““Pax MundiPax Mundi”” Shapes ShapesGood combination of interactive 3D graphicsand parameterizable procedural constructs.

Sculptures by Naum GaboSculptures by Naum Gabo

Pathway on a sphere:

Edge of surface is like seam of tennis- or base-ball;

2-period Gabo curve.

2-period 2-period ““Gabo CurveGabo Curve””

Approximation with quartic B-splinewith 8 control points per period,but only 3 DOF are used (symmetry!).

4-period 4-period ““Gabo CurveGabo Curve””

Same construction as for as for 2-period curve

Pax MundiPax Mundi Revisited Revisited Can be seen as:

Amplitude modulated, 4-period Gabo curve

2-period Gabo sculpture2-period Gabo sculpture

Tennis ball – or baseball – seam used assweep curve.

““Viae GlobiViae Globi”” Family Family (Roads on a Sphere)(Roads on a Sphere)

2 3 4 5 periods

Many Different Many Different ““Viae GlobiViae Globi”” Models Models

Emulation; Define Master PatternEmulation; Define Master Pattern

Use 4 copies.

Master to make a mold from.

Alignment tab

Model of Master Part Made with FDMModel of Master Part Made with FDM

4 pieces make the whole sculpture

Joe ValasekJoe Valasek’’s CNC Milling Machines CNC Milling Machine

Styrofoam milling machine

Design of Two-Part MasterDesign of Two-Part Master

Alignment tabs for easy assembly

Subdivide into Subdivide into TwoTwo Master Segments Master Segments

Machined Master Pattern #2Machined Master Pattern #2

(Cut) Master (Cut) Master Silicone Rubber MoldSilicone Rubber Mold

MoldMold Several (4) Wax Copies Several (4) Wax Copies

SpruingSpruing the the Wax PartsWax Parts for Casting for Casting

Ceramic Slurry ShellCeramic Slurry Shell Around Wax Part Around Wax Part

Taking the Taking the ShellShell out of the out of the KilnKiln

ShellShell Ready Ready for Castingfor Casting

The The PourPour

Casting with Casting with Liquid BronzeLiquid Bronze

Freeing the Freeing the Bronze CastBronze Cast

Assembling the SegmentsAssembling the Segments

The The ““GrowingGrowing”” Ribbon Ribbon

The Assembly is Too Squat !!The Assembly is Too Squat !!

Changing the CurvatureChanging the Curvature

PHYSICS is important too ...PHYSICS is important too ...

not just Geometry !not just Geometry !

Static DisplacementStatic Displacement

“Pax Mundi” “Music of the Spheres”

red = maximal, blue = minimal displacement

Grinding the Welded Seams,Grinding the Welded Seams,Polishing the SurfacePolishing the Surface

Applying PatinaApplying Patina

Front Door of the ...Front Door of the ...

H&R Block Building

The Final DestinationThe Final Destination

Steve Reinmuth Tightening the BoltsSteve Reinmuth Tightening the Bolts

Brent Collins Polishing Our BabyBrent Collins Polishing Our Baby

Team effort: Brent Collins, Steve Reinmuth, Carlo Séquin

ObservationsObservations Engineering considerations took much more time than

the original shape design. Scale partitioning of shape

How to create the master pattern

Fabrication issue become a much bigger concern when you plan to make several copies ! Complexity and reusability of molds

Work required to finishing a sculpture

Yet Another Medium: Yet Another Medium: StoneStone

“Pillar of Engineering”

Sponsored by Paul Suciu (EECS alum)

Pillar of Engineering at UCBPillar of Engineering at UCB

Fall 2011: CS 285 at UCBFall 2011: CS 285 at UCBSolid Modeling and Rapid PrototypingSolid Modeling and Rapid Prototyping

Give the students some experience with fabrication issues!

Dissection puzzles are an ideal medium:

-- they enhance the spatial visualization skills;

-- they force students to address issues of accuracy, tolerances, materials properties.

One Problem StatementOne Problem Statement

Design a two- or three-piece geometrical puzzle in which a shape splits into all congruent parts via a helical screw motion.

Teams of 3-4 students

Conceptual discussions in class

A first design + Individual feedback

Initial design to be fabricated on FDM machine

2nd, “final” design, hopefully yielding a working puzzle

ExecutionExecution

Simple Helicoidal DissectionsSimple Helicoidal Dissections

3-part CAD model Cross section Scaling function

A sweep producing a tear-drop shape

z

First FDM PartsFirst FDM Parts

Rapid Prototyping with FDMRapid Prototyping with FDM

A Look Into the FDM MachineA Look Into the FDM Machine

A sculpture-build in progress; note grey support!

2 NOZZLES

A Second Set of PartsA Second Set of PartsThere are still problems:

The parts may not slide together completely!

Advanced Helicoidal DissectionsAdvanced Helicoidal Dissections

• This design started with the outer shape: a cube• then partitioned it in to 3 parts with helicoidal cuts

Generalization: Multi-Prong DissectionsGeneralization: Multi-Prong Dissections

Design a straight configuration and then twist the whole thing

Two 3-Prong PartsTwo 3-Prong Parts

. . . and they fit together!. . . and they fit together!

How to get the initial creative How to get the initial creative concept into the computer ?concept into the computer ?

From a vague vision in your head . . .

or a doodle on a piece of paper . . .

or some twisted pipe-cleaners . . .

to a first CAD model in a computer.

Tele-Collaborative VR Workstation Tele-Collaborative VR Workstation for Designing Across the Internetfor Designing Across the Internet

(with Sara McMains, ME)(with Sara McMains, ME)

See in 3D,Touch, feel,Annotate,Modify,Share,

Discuss …

Collaborative VR WorkstationCollaborative VR Workstation

A student interacting with a Ford Explorer model displayed on the workstation

(simulated 3D effect showing the part where the user perceives it to be).

Model AnnotationModel Annotation

Drawing on a virtual bunny with a brush tool with haptic force-feedback.

CAD tools for Ideation, Informal PrototypingCAD tools for Ideation, Informal Prototyping

These are things I am using:

wire, paper, scotch-tape, paper clips, styrofoam, clay, …

Touch and proprioception (knowing where your hands are), as well as the elastic properties of the material used,play an important role.

““Frank GehryFrank Gehry”” Style of Design Style of Design

Drape some cloth over any kind of support . . . and then change it again a few days later!

CAD ManifestoCAD Manifesto

We want to add real objects into the VR world !

Not only turn VR shapes into physical objects,

or superpose VR entities onto the real worldto produce an Augmented Reality.

We want to grab a physical artifact:

a toy, a slat, a metal band, a peace of velvet, . . .

shape it, deform it, bend it, . . . and go “click” !

-- and have that shape show up in a design file!

Perhaps based on a Kinect or Structured Light …

CAD Manifesto (cont.)CAD Manifesto (cont.)

We want a shape-editing & composition system that:

mimiks the best of: clay, wire, paper, scotch-tape, styrofoam …

without the adversity of: messy glue, gravity, strength limits …

makes available pseudo-physical materials that bend as nicely as steel wire, or stretch like a nylon hose, but are strong as titanium, and as transparent as quartz, and … (your own priorities).

Who is going to sign up ?

Q U E S T I O N S ?Q U E S T I O N S ?

Cubic Burr PuzzleCubic Burr Puzzle

3D Dissection Puzzles – an educational tool: Train 3-D spatial thinking

Give “hands-on” feedback about accuracy & tolerances

Fun artifacts to take away as souvenirs; good “motivators”

Burr Puzzle AssemblyBurr Puzzle Assembly

Some ObservationsSome Observations

Interactive graphics ==> enhanced creativity

I would like a more expressive user interface – particularly for the first stages of capturing an idea and getting it into the computer.

I am still using paper, wire, styrofoam, etc ...to explore new ideas.

However, the computer is great: for refining and optimizing a design,

for incrementally extending the scope.

Inverse 3D Modeling Inverse 3D Modeling (with Jimmy Andrews)(with Jimmy Andrews)

Capture a hierarchically flat model in a parameterized procedural description that fits the users plan and can easily be modified.

• Yellow strokes (#1) defines the start of a progressive sweep.

• An optional 2nd stroke extends or restricts the sweep range.

Versatility of Progressive SweepsVersatility of Progressive Sweeps• Different starting strokes and different error tolerances result in a wide variety of possible extracted sweeps.

• Sweep path and profiles can be edited independently.

• Surface details with respect to the extracted sweep can be conserved and reapplied after any editing moves, or they can be ignored or smoothed out.

Editing On-the-FlyEditing On-the-Fly• A rotational sweep around the z-axis is specified.• A “thick profile” is extracted by collapsing φ-component.

• Portions of the “thick profile” can be selected and moved;• the corresponding surface elements move radially:• (a) the whole nose and cheeks area is enlarged;• (b) only the nose is stretched.

(a) (b)

““Music of the SpheresMusic of the Spheres””

Original by Brent Collins Generated maquette (Séquin)

Commission for a new Science Building, Missouri Western State University, St. Joseph

Re-Proportioned SculptureRe-Proportioned Sculpture

““Music of the SpheresMusic of the Spheres”” (6 views) (6 views)

Fabricating Fabricating ““Music of the SpheresMusic of the Spheres””

The molds for some pieces One of the wax replica

Applying Plaster SlurryApplying Plaster Slurry

Some Segments Will Be Cast HollowSome Segments Will Be Cast Hollow