CAP4730: Computational Structures in Computer Graphics Graphics Research
Graphics Community • SIGGRAPH - Special Interest Group - Graphics • premiere graphics conference held annually • go here for the latest in graphics research • computer graphics as art/art festival • special effects/movies • technical papers • immerging technologies • ~50000 people from all over the world • UNC has perennially had a strong presence here • Eurographics, Interactive 3D Graphics (I3D), Visualization, IEEE Virtual Reality, Virtual Reality Symposium on Technology • Unlike many fields, conferences are more important than journals
Graphics Education • Universities that have a strong graphics (with an interactive or photorealistic focus) • University of North Carolina http://www.cs.unc.edu/Research/Graphics-Image/ • University of Utah • Brown University • Stanford University • MIT • Cornell University • CalTech • Georgia Tech • University of California at Berkley
Graphics in Industry • Microsoft Graphics Research • Mitsubishi Engineering Research Labs • Alias|Wavefront • Pixar • Dreamworks Studio • SGI (Silicon Graphics)
Areas of Graphics Research • NOT an exhaustive list! • Modeling • Compression • Surfaces • Lighting and Shading • Image Based Rendering • Model Acquisition • Simplification/Level of Detail • Light Fields • Rendering • Non-Photorealistic Rendering • Interactive Techniques
Modeling Different Materials • Cloth • Liquids • Fire • Hair/Fur • Skin • CDs • Grass • What are the common denominators here?
Global Illumination • Radiosity • Radiosity as textures • Bidirection Reflectance Distribution Function (BRDF) • Light as rays, doesn’t do everything
Modelling • Massive Models • models of 100,000,000 triangles • http://www.cs.unc.edu/~walk/research/index.html • Replace geometry with images • Warp images • Occlusion culling • Cell and Portal culling • Level of detail
Volume Visualization • Medical Data • MRI Slices -> 3D • Data sizes • Extracting useful information • Accuracy is now VERY important!
Simplification/Level of Detail • Objects farther away can be represented with less detail • http://www.cs.unc.edu/~walk/hlod/ • How do we “remove” triangles? • What are the advantages and disadvantages? • What about objects that stretch the entire length of the object? • Can we do this automatically?
Collision Detection • Determining intersections between models • Resolution of collisions • Where is the intersection? • Normal of surfaces • Depth of intersection • Multiple collisions
Image Based Rendering • We use to think of photos as 2D and geometry as 3D and distinct • IBR says 2D images have 3D information.
Non Photorealistic Rendering • Cartoons • Pen/Pencil • Paints • Art • Drawing Styles
Virtual Environments • Virtual Reality • Trackers • Rendering • Haptics • Avatars • Hybrid Reality
Using Graphics as tools • Office of real soon now • Nanomanipulator
Human Computer Interaction • What is a user interface? • Why do we care about design? • We see this all the time. • What’s good about the design of this error box? • The user knows there is an error • What’s poor about the design of this error box? • Discouraging • Not enough information • No way to resolve the problem (instructions or contact info)
My Choice • iPod by Apple Computers • Pros: • portable • power • ease of use • # of controls • Cons: • scratches easily • no speech for car use • proprietary
HCI Community • Academics/Industry Research • Taxonomies • Theories • Predictive models • Experimenters • Empirical data • Product design • Other areas (Sociologists, anthropologists, managers) • Motor • Perceptual • Cognitive • Social, economic, ethics
HCI Tools • Sound • 3D • Animation • Video • Devices • Size (small->very large) • Portable (PDA, phone) • Plasticity • Context sensitive/aware • Personalizable • Ubiquitous
Usability Requirements • Goals: • Usability • Universality • Usefulness • Achieved by: • Planning • Sensitivity to user needs • Devotion to requirements analysis • Testing
Bad Interfaces • Encumbering • Confusing • Slow • Trust (ex. windows crashing) • What makes it hard? • Varies by culture • Multiple platforms • Variety of users • Think of a game you’ve played with a bad interface • UNIX
Example • Five fastest places to click on for a right-handed user?
Example • What affects time?
Virtual Reality Definition • What is virtual reality? • Virtual – • Being in essence or effect, but not in fact • Example VRAM • Reality – • The state or quality of being real. Something that exists independently of ideas concerning it. Something that constitutes a real or actual thing as distinguished from something that is merely apparent.” • What was the first VR?
Ivan Sutherland’s The Ultimate Display “Don’t think of that thing as a screen, think of it as a window, a window through which one looks into a virtual world. The challenge to computer graphics is to make that virtual world look real, sound real, move and respond to interaction in real time, and even feel real.”
Key Elements of Virtual Reality Experience • Virtual World - content of a given medium • screen play, script, etc. • actors performing the play allows us to experience the virtual world • Immersion – sensation of being in an environment • mental immersion – suspension of disbelief • physical immersion – bodily entering the medium • Related to presence – (mentally immersed) the participant’s sensation of being in the virtual environment (Slater) Walking Experiment at UNC – Chapel Hill
Augmented Reality • A combination of a real scene viewed by a user and a virtual scene generated by a computer that augments the scene with additional information. Ultrasound Visualization Research at UNC – Chapel Hill All Virtual Objects All Real Objects
Immersive Technology • Head-mounted Display • Optical System • Image Source (CRT or LCD) • Mounting Apparatus • Earphones • Position Tracker
Immersive Technology • Multi-screen Projection of stereoscopic images (CAVE)
Immersive Technology • Single large stereoscopic display • Projection-based • Head-tracked • Possible tracking of hands and arms. • Brings virtual objects into the physical world
User’s perspective • Setting • Objects in world • Other participants • Active/Passive • Factory Simulation • Architectural Walkthrough
Immersive Virtual Characters for Educating Medical Communication Skills J. Hernendez, A. Stevens, D. S. Lind Department of Surgery (College of Medicine) M. Duerson Department of Community Health and Family Medicine (College of Medicine) K. Johnsen, A. Raij, R. Dickerson, B. Lok Department of Computer and Information Science and Engineering (College of Engineering) R. Ferdig College of Education The University of Florida, Gainesville, FL J. Jackson, M. ShinDepartment of Computer Science The University of North Carolina at Charlotte, Charlotte, NC Sebastian Foti, Juan Cendan, Peggy Werner Associated Faculty
Future Work • Future collaborators • UF College of Education • Medical College of Georgia (MCG) • Now n=20, future n=120 students / year (MCG) • Evaluate VP vs SP • Non-verbal communication • Body lean • Eye gaze • Real Speech vs Text to Speech • Negative training transfer
At assembly design stage: Several constructed parts Many CAD models for parts yet to be constructed Unverified assembly plans How can we verify the assembly plan? Driving Application: Engineering Design Evaluation Motivation: • Finding design flaws earlier will save time and money • Virtual environments have difficulty simulating hands-on assembly • Support team based interaction To be built in 2008 We only have this in 2005
Capturing the Physical Model Reconstruction from multiple scans Scanning Define color markers Interaction in ME
Skill Set • “Oh I don’t want to program, I just want to create stuff” • Architect or Car analogy • Programming -> tool to create what is in your imagination • Programming proficiency goal: be able to code anything that you imagine • To do what you saw before we use: • C/C++, OpenGL, many different libraries • Math, math, and yet more math!!! • Differential equations (simulations, physics engines), linear algebra (transforms, 3D manipulations), statistics
Graduate School • Programming Team Lead at RockStar Games • Worked on Midnight Club 2 • Renderman Developer at Pixar • Worked on the Jellyfish of Nemo and The Incredibles • Software Engineer for Interactive Media for Disney • Worked on Toon Town, online capable titles • Worked at 989 Sports, EA Sports, Freedom Force, etc. • What did they all have in common? • Published scientific journals in computer science • Graduate school in computer science • Worked on efficient collision detection, particle systems, curved surfaces, virtual reality, etc. • All had • GRE scores in the top 10% • Went to a top graduate school (admission is tough) • Strong math and science and coding • Why would a CS professor want to work with you?
Interested? Take the following… • CAP4730 Computational Structures in Computer Graphics (Fall ’05) • CAP4930/6930 Design and Creation of Virtual Environments (Fall ’05) • CAP4930/6930 Human-Computer Interaction (Spring ’06?) • Computational Geometry (Spring ’06)? • Computer Simulation Concepts (Fall ’05)
Virtual Experiences Group • PhD Students (4) • Kyle Johnsen • John Quarrels • Andrew Raij • Xiyong Wang • Undergraduates (4) • Robert Dickerson • Sayed Hashimi • Andrew Joubert • Art Homs • Alumni (4) • Cyrus Harrison (MS) • George Mora (MS) • Andrew Joubert (BS) • Samuel Preston (BS) • John Samuelsen (BS) Thank you! Questions?