VR-Conference, 3/06/2012 Taking the "Virtual" Out of VR Carlo H. Séquin University of California, Berkeley.
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VR-Conference, 3/06/2012 Taking the "Virtual" Out of VR Carlo H. Séquin University of California, Berkeley Geometry ! Descriptive Geometry – love since high school Descriptive Geometry CCD TV Video Camera, Bell Labs 1973 Chip Layout and Camera Geometry RISC : Reduced Instruction Set Computers The Berkeley RISC chip (1981): Katevenis, Sherburne, Patterson, Séquin 3D Architectural Geometry Design and Construction of Soda Hall, 1985-1994 Early Soda Hall WalkThru (1992) Soda Hall WalkThru Center for Information Technology Research in the Interest of Society CITRIS Building Startup Space Committees Plenary 9 Looking South from the Engineering Esplanade CITRIS Building Startup Space Committees Plenary 10 A few typical spaces . . . Small conference room Signature conference room (sixth floor) Entrance corridor Entrance to main auditorium CITRIS Building Startup Space Committees Plenary 11 Main Auditorium (third floor) CITRIS Building Startup Space Committees Plenary 12 CITRIS: Digging a Hole Pouring the Mud Slab Wall Construction: ReBar Steel Frame Rising Fearless Steel Workers Facade Going Up Building Almost Complete Joy-Ride on the Tower Crane Complex Work on the Interior My Passion for Sculpture My love for geometry and abstract sculpture emerged long before I learned to play with computers. Thanks to: Alexander Calder, Naum Gabo, Max Bill, M.C. Escher, Frank Smullin, ... Artistic Geometry Tubular Sculptures Frank Smullin (1943–1983) Apple II program for calculating intersections DAC, Nashville, 1981. Granny-Knot-Lattice (Séquin, 1981) Rendered with The Berkeley UNIgrafiX System Strands in Granny-Knot-Lattice (1990) 3D Hilbert Curves (1998) Hilbert_64 and Hilbert_512 Realization by ProMetal (2005) Metal sintering and infiltration process Early Brent Collins Sculptures Sculptures by Brent Collins (1990-94) All photos by Phillip Geller Leonardo Foil On Knot-Spanning Surfaces: An Illustrated Essay on Topological Art George K. Francis with Brent Collins Scherk’s 2nd Minimal Surface Normal “biped” saddles “Scherk Tower” Generalization to higher-order saddles (monkey saddle) 2nd and 3rd Order “Scherk Towers” “Hyperbolic Hexagon” by B. Collins 6 saddles in a ring = “wound up” 6-story Scherk tower 6 holes passing through symmetry plane at ±45º Brent Collins “Hyperbolic Hexagon II” Inauguration Sutardja Dai Hall 2/27/09 “Hyperbolic Hexagon” by B. Collins Has some strange coincidences Discussion: What if … we added more stories ? or introduced a twist before closing the ring ? Closing the Loop straight or twisted “Twisted Scherk Tower” “Scherk-Collins Toroids” “Hyperbolic Heptagon” - Paper Skeleton Brent Collins’ Prototyping Process Armature for the Hyperbolic Heptagon Mockup for the Saddle Trefoil Time-consuming ! (1-3 weeks) Sculpture Generator 1, GUI http://www.cs.berkeley.edu/~sequin/GEN/Sculpture_Generator/ V-art Virtual Glass Scherk Tower with Monkey Saddles (Radiance 40 hours) Jane Yen Collins’ Fabrication Process Layered laminated main shape Wood master pattern for sculpture Example: “Vox Solis” “Vox Solis” by Brent Collins Photo by Phillip Geller Séquin’s “Minimal Saddle Trefoil” Stereo- lithography master Slices through “Minimal Trefoil” 50% 30% 23% 10% 45% 27% 20% 5% 35% 25% 15% 2% Brent’s Trefoil Profiled Slice through “Heptoroid” One thick slice thru sculpture, from which Brent can cut boards and assemble a rough shape. Traces represent: top and bottom, as well as cuts at 1/4, 1/2, 3/4 of one board. Emergence of the Heptoroid (1) Assembly of the precut boards Emergence of the Heptoroid (2) Forming a continuous smooth edge Emergence of the Heptoroid (3) Smoothing the whole surface The Finished Heptoroid at Fermi Lab Art Gallery (1998). . . . and a Whole Lot of Plastic Models Rapid Prototyping with FDM A Look Into the FDM Machine 2 NOZZLES “Galapagos 6” sculpture in progress Brent Collins’ “Pax Mundi” 1997: wood, 30”diam. 2006: Commission from H&R Block, Kansas City to make a 70”diameter version in bronze. My task: to define the master geometry. How to Model “Pax Mundi”... Already addressed that question in 1998: Pax Mundi could not be done with Sculpture Generator I Needed Used First: a more general program ! the Berkeley SLIDE environment. Needed to find the basic paradigm Sculptures by Naum Gabo Pathway on a sphere: Edge of surface is like seam of tennis- or base-ball; 2-period Gabo curve. 2-period “Gabo Curve” Approximation with quartic B-spline with 8 control points per period, but only 3 DOF are used (symmetry!). 4-period “Gabo Curve” Same construction as for as for 2-period curve Pax Mundi Revisited Can be seen as: Amplitude modulated, 4-period Gabo curve SLIDE-GUI for “Pax Mundi” Shapes Good combination of interactive 3D graphics and parameterizable procedural constructs. 2-period Gabo sculpture Tennis ball – or baseball – seam used as sweep curve. “Viae Globi” Family 2 3 (Roads on a Sphere) 4 5 periods “Via Globi 5” (Virtual Wood) Wilmin Martono Many Different “Viae Globi” Models Target Geometry Constraints: • Bronze; 70” diameter • Less than 1500 pounds • Less than $50’000 • Maintain beauty, strength • Minimize master geometry Emulation; Define Master Pattern Master to make a mold from. Alignment tab Use 4 copies. Model of Master Part Made with FDM 4 pieces make the whole sculpture Joe Valasek’s CNC Milling Machine Styrofoam milling machine Design of Two-Part Master Alignment tabs for easy assembly Subdivide into Two Master Segments Machined Master Pattern #2 (Cut) Master Silicone Rubber Mold Mold Several (4) Wax Copies Spruing the Wax Parts for Casting Ceramic Slurry Shell Around Wax Part Taking the Shell out of the Kiln Shell Ready for Casting The Pour Casting with Liquid Bronze Freeing the Bronze Cast Assembling the Segments The “Growing” Ribbon The Assembly is Too Squat !! Changing the Curvature PHYSICS is important too ... not just Geometry ! Grinding the Welded Seams, Polishing the Surface Applying Patina Front Door of the ... H&R Block Building The Final Destination Steve Reinmuth Tightening the Bolts Brent Collins Polishing Our Baby Team effort: Brent Collins, Steve Reinmuth, Carlo Séquin Observations 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 “Music of the Spheres” Original by Brent Collins Generated maquette (Séquin) Commission for a new Science Building, Missouri Western State University, St. Joseph Re-Proportioned Sculpture “Music of the Spheres” (6 views) Static Displacement red = maximal, blue = minimal “Pax Mundi” displacement “Music of the Spheres” Fabricating “Music of the Spheres” The molds for some pieces One of the wax replica Applying Plaster Slurry Some Segments Will Be Cast Hollow Yet Another Medium: Stone “The Three Pillars of Engineering” Math – Materials – Physics(Science) Sponsored by Paul Suciu (EECS alum) Cubic 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” Simple Helicoidal Dissections Design a 2- or 3-piece puzzle in which a simple shape partitions into all congruent parts via a helical screw motion A Puzzle That Cannot Be Taken Apart With Only Two Hands It needs a coordinated action of several (groups of) parts to be disassembled SNOEYINK, J. and STOLFY, J. 1993. Objects that cannot be taken apart with two hands. SCG '93 San Diego, pp 247-256. Burr Puzzle Assembly CADAM: Rapid Prototyping with Paul Wright (ME) Physical Rapid Prototypes: For early user testing, and hands-on feedback in application context. Zcorp 3D-printer FDM EE – ME Design Domain Coupling (with Paul Wright, ME) Button Mote Design from NEST Group Coupling • PCB Contact Pads and Lid Access Holes are considered features. • Access Holes are coupled to Contact Pads geometrically by position and size. • Alteration of center location of Contact Pads (Electrical Domain) will influence Access Holes (Mechanical Domain) center locations. Input / Output to / from VR PART A: Take the “virtual” out of VR VR Real physical objects PART B: Put something “real” into the VR-domain Enter an initial CAD model into the computer Inverse 3D Modeling (with Jimmy Andrews) Supported by NSF award #CMMI-1029662 (EDI) 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 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-Fly • A rotational sweep around the z-axis is specified. • A “thick profile” is extracted by collapsing φ-component. • • • • (a) (b) 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. Tele-Collaborative VR Workstation for Designing Across the Internet (with Sara McMains, ME) See in 3D, Touch, feel, Annotate, Modify, Share, Discuss … Collaborative 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 Annotation Drawing on a virtual bunny with a brush tool with haptic force-feedback. CAD 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 Gehry” Style of Design Drape some cloth over any kind of support . . . and then change it again a few days later! CAD 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 world to 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.) 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 ? QUESTIONS ?