Graphics ResearchGraphics Research

CAP4730: Computational Structures in Computer Graphics

Graphics CommunityGraphics Community SIGGRAPH - Special Interest Group - GraphicsSIGGRAPH - Special Interest Group - Graphics

– premiere graphics conference held annuallypremiere graphics conference held annually– go here for the latest in graphics researchgo here for the latest in graphics research

computer graphics as art/art festivalcomputer graphics as art/art festival special effects/moviesspecial effects/movies technical paperstechnical papers immerging technologiesimmerging technologies

– ~50000 people from all over the world~50000 people from all over the world– UNC has perennially had a strong presence hereUNC has perennially had a strong presence here

Eurographics, Interactive 3D Graphics (I3D), Visualization, IEEE Eurographics, Interactive 3D Graphics (I3D), Visualization, IEEE Virtual Reality, Virtual Reality Symposium on TechnologyVirtual Reality, Virtual Reality Symposium on Technology

Unlike many fields, conferences are more important than journalsUnlike many fields, conferences are more important than journals

Graphics EducationGraphics Education Universities that have a strong graphics (with an Universities that have a strong graphics (with an

interactive or photorealistic focus)interactive or photorealistic focus)– University of North Carolina University of North Carolina

http://www.cs.unc.edu/Research/Graphics-Image/ http://www.cs.unc.edu/Research/Graphics-Image/ – University of UtahUniversity of Utah– Brown UniversityBrown University– Stanford UniversityStanford University– MITMIT– Cornell UniversityCornell University– CalTechCalTech– Georgia TechGeorgia Tech– University of California at BerkleyUniversity of California at Berkley

Graphics in IndustryGraphics in Industry

Microsoft Graphics ResearchMicrosoft Graphics Research Mitsubishi Engineering Research Mitsubishi Engineering Research

LabsLabs Alias|WavefrontAlias|Wavefront PixarPixar Dreamworks StudioDreamworks Studio SGI (Silicon Graphics)SGI (Silicon Graphics)

Areas of Graphics Areas of Graphics ResearchResearch

NOT an exhaustive list!NOT an exhaustive list! ModelingModeling CompressionCompression SurfacesSurfaces Lighting and ShadingLighting and Shading Image Based RenderingImage Based Rendering Model AcquisitionModel Acquisition Simplification/Level of DetailSimplification/Level of Detail Light FieldsLight Fields RenderingRendering Non-Photorealistic RenderingNon-Photorealistic Rendering Interactive TechniquesInteractive Techniques

Modeling Different Modeling Different MaterialsMaterials

ClothCloth LiquidsLiquids FireFire Hair/FurHair/Fur SkinSkin CDsCDs GrassGrass What are the common denominators here?What are the common denominators here?

Global IlluminationGlobal Illumination RadiosityRadiosity Radiosity as Radiosity as

textures textures Bidirection Bidirection

Reflectance Reflectance Distribution Distribution Function (BRDF)Function (BRDF)

Light as rays, Light as rays, doesn’t do doesn’t do everythingeverything

ModellingModelling Massive ModelsMassive Models

– models of 100,000,000 models of 100,000,000 trianglestriangles

– http://www.cs.unc.edu/http://www.cs.unc.edu/~walk/research/~walk/research/index.htmlindex.html

– Replace geometry with Replace geometry with imagesimages

– Warp imagesWarp images– Occlusion cullingOcclusion culling– Cell and Portal cullingCell and Portal culling– Level of detailLevel of detail

Volume VisualizationVolume Visualization

Medical DataMedical Data MRI Slices -> 3DMRI Slices -> 3D Data sizesData sizes Extracting useful Extracting useful

informationinformation Accuracy is now Accuracy is now

VERY important!VERY important!

Simplification/Level of Simplification/Level of DetailDetail

Objects farther away can be represented with less detailObjects farther away can be represented with less detail http://www.cs.unc.edu/~walk/hlod/http://www.cs.unc.edu/~walk/hlod/ How do we “remove” triangles?How do we “remove” triangles? What are the advantages and disadvantages?What are the advantages and disadvantages? What about objects that stretch the entire length of the What about objects that stretch the entire length of the

object?object? Can we do this automatically?Can we do this automatically?

Collision DetectionCollision Detection

Determining intersections between Determining intersections between modelsmodels

Resolution of collisionsResolution of collisions Where is the intersection?Where is the intersection? Normal of surfacesNormal of surfaces Depth of intersectionDepth of intersection Multiple collisionsMultiple collisions

Image Based RenderingImage Based Rendering

We use to think We use to think of photos as 2D of photos as 2D and geometry and geometry as 3D and as 3D and distinctdistinct

IBR says 2D IBR says 2D images have 3D images have 3D information.information.

Non Photorealistic Non Photorealistic RenderingRendering

CartoonsCartoons Pen/PencilPen/Pencil PaintsPaints ArtArt Drawing StylesDrawing Styles

Virtual EnvironmentsVirtual Environments

Virtual RealityVirtual Reality TrackersTrackers RenderingRendering HapticsHaptics AvatarsAvatars Hybrid RealityHybrid Reality

Using Graphics as toolsUsing Graphics as tools

Office of real soon nowOffice of real soon now NanomanipulatorNanomanipulator

Human Computer Human Computer InteractionInteraction

What is a user interface?What is a user interface? Why do we care about design?Why do we care about design?

We see this all the time. We see this all the time. – What’s good about the design of this error box?What’s good about the design of this error box?

The user knows there is an errorThe user knows there is an error– What’s poor about the design of this error box?What’s poor about the design of this error box?

DiscouragingDiscouraging Not enough informationNot enough information No way to No way to resolveresolve the problem (instructions or contact the problem (instructions or contact

info)info)

My ChoiceMy Choice iPod by Apple iPod by Apple

ComputersComputers Pros:Pros:

– portableportable– powerpower– ease of useease of use– # of controls# of controls

Cons:Cons:– scratches easilyscratches easily– no speech for car no speech for car

useuse– proprietaryproprietary

HCI CommunityHCI Community Academics/Industry Academics/Industry

Research Research – TaxonomiesTaxonomies– TheoriesTheories– Predictive modelsPredictive models

Experimenters Experimenters – Empirical dataEmpirical data– Product designProduct design

Other areas (Sociologists, Other areas (Sociologists, anthropologists, managers)anthropologists, managers)– MotorMotor– PerceptualPerceptual– CognitiveCognitive– Social, economic, ethicsSocial, economic, ethics

HCI ToolsHCI Tools SoundSound 3D3D AnimationAnimation VideoVideo DevicesDevices

– Size (small->very large)Size (small->very large)– Portable (PDA, phone)Portable (PDA, phone)– PlasticityPlasticity

Context Context sensitive/awaresensitive/aware

PersonalizablePersonalizable UbiquitousUbiquitous

Usability RequirementsUsability Requirements Goals:Goals:

– UsabilityUsability– UniversalityUniversality– UsefulnessUsefulness

Achieved by:Achieved by:– PlanningPlanning– Sensitivity to user Sensitivity to user

needsneeds– Devotion to Devotion to

requirements requirements analysisanalysis

– TestingTesting

Bad InterfacesBad Interfaces EncumberingEncumbering ConfusingConfusing SlowSlow Trust (ex. windows Trust (ex. windows

crashing)crashing) What makes it hard?What makes it hard?

– Varies by cultureVaries by culture– Multiple platformsMultiple platforms– Variety of usersVariety of users

Think of a game Think of a game you’ve played with a you’ve played with a bad interfacebad interface– UNIXUNIX

ExampleExample Five fastest places to click on for a Five fastest places to click on for a right-handed user?right-handed user?

ExampleExample What affects time?What affects time?

Virtual Reality DefinitionVirtual Reality Definition

What is virtual reality?What is virtual reality?– Virtual – Virtual –

Being in essence or effect, but not in factBeing in essence or effect, but not in fact Example VRAMExample VRAM

– Reality –Reality – The state or quality of being real. Something The state or quality of being real. Something

that exists independently of ideas concerning that exists independently of ideas concerning it. Something that constitutes a real or actual it. Something that constitutes a real or actual thing as distinguished from something that is thing as distinguished from something that is merely apparent.”merely apparent.”

– What was the first VR?What was the first VR?

What was the first VR?What was the first VR?

Ivan Sutherland’s Ivan Sutherland’s The Ultimate DisplayThe Ultimate Display

““Don’t think of that thing as a Don’t think of that thing as a screen, think of it as a screen, think of it as a window, a window through window, a window through which one looks into a virtual which one looks into a virtual world. The challenge to world. The challenge to computer graphics is to make computer graphics is to make that virtual world look real, that virtual world look real, sound real, move and sound real, move and respond to interaction in real respond to interaction in real time, and even feel real.”time, and even feel real.”

Key Elements of Virtual Key Elements of Virtual Reality ExperienceReality Experience

Virtual World - content of a given Virtual World - content of a given mediummedium– screen play, script, etc.screen play, script, etc.– actors performing the play allows us to actors performing the play allows us to

experience the virtual worldexperience the virtual world

Immersion – sensation of being in an Immersion – sensation of being in an environmentenvironment– mental immersion – suspension of mental immersion – suspension of

disbeliefdisbelief– physical immersion – bodily entering physical immersion – bodily entering

the mediumthe medium– Related to Related to presencepresence – (mentally – (mentally

immersed) the participant’s sensation immersed) the participant’s sensation of being in the virtual environment of being in the virtual environment (Slater)(Slater)

Walking Experiment atUNC – Chapel Hill

Augmented RealityAugmented Reality

A combination of a A combination of a real scene viewed real scene viewed by a user and a by a user and a virtual scene virtual scene generated by a generated by a computer that computer that augments the augments the scene with scene with additional additional information.information.

Ultrasound Visualization Research atUNC – Chapel Hill

All Virtual Objects All Real Objects

Immersive TechnologyImmersive Technology Head-mounted Head-mounted DisplayDisplay– Optical SystemOptical System– Image Source (CRT Image Source (CRT

or LCD)or LCD)– Mounting ApparatusMounting Apparatus– EarphonesEarphones– Position TrackerPosition Tracker

Immersive TechnologyImmersive Technology Multi-screen Projection Multi-screen Projection

of stereoscopic images of stereoscopic images (CAVE)(CAVE)

Immersive TechnologyImmersive Technology

Single large Single large stereoscopic stereoscopic displaydisplay– Projection-basedProjection-based– Head-trackedHead-tracked– Possible tracking of Possible tracking of

hands and arms.hands and arms.– Brings virtual Brings virtual

objects into the objects into the physical worldphysical world

User’s perspectiveUser’s perspective SettingSetting Objects in worldObjects in world Other participantsOther participants Active/PassiveActive/Passive

– Factory SimulationFactory Simulation– Architectural Architectural

WalkthroughWalkthrough

Immersive Virtual Characters for Immersive Virtual Characters for Educating Medical Communication SkillsEducating Medical Communication Skills

J. Hernendez, A. Stevens, D. S. LindJ. Hernendez, A. Stevens, D. S. Lind Department of Surgery (College of Medicine)Department of Surgery (College of Medicine)

M. DuersonM. Duerson Department of Community Health and Family Medicine (College Department of Community Health and Family Medicine (College of Medicine) of Medicine)

K. Johnsen, A. Raij, R. Dickerson, B. LokK. Johnsen, A. Raij, R. Dickerson, B. LokDepartment of Department of Computer and Information Science and Computer and Information Science and Engineering (College of Engineering)Engineering (College of Engineering)

R. FerdigR. FerdigCollege of EducationCollege of Education The University of Florida, Gainesville, FLThe University of Florida, Gainesville, FL

J. Jackson, M. ShinJ. Jackson, M. ShinDepartment of Department of Computer Science Computer Science The University of North Carolina at Charlotte, Charlotte, NCThe University of North Carolina at Charlotte, Charlotte, NC

Sebastian Foti, Juan Cendan, Peggy WernerSebastian Foti, Juan Cendan, Peggy WernerAssociated FacultyAssociated Faculty

Future WorkFuture Work Future collaboratorsFuture collaborators

– UF College of Education UF College of Education – Medical College of Medical College of

Georgia (MCG)Georgia (MCG) Now n=20, future n=120 Now n=20, future n=120

students / year (MCG)students / year (MCG) Evaluate VP vs SPEvaluate VP vs SP Non-verbal Non-verbal

communicationcommunication– Body leanBody lean– Eye gazeEye gaze

Real Speech vs Text to Real Speech vs Text to Speech Speech

Negative training transferNegative training transfer

Driving Application: Driving Application: Engineering Design Engineering Design

EvaluationEvaluation

At assembly design stageAt assembly design stage::– Several constructed parts Several constructed parts – Many CAD models for parts yet to Many CAD models for parts yet to

be constructedbe constructed– Unverified assembly plansUnverified assembly plans

How can we verify the assembly How can we verify the assembly plan?plan?

To be built in 2008We only have this in 2005

MotivationMotivation::– Finding design flaws earlier will Finding design flaws earlier will

save time and moneysave time and money– Virtual environments have Virtual environments have

difficulty simulating hands-on difficulty simulating hands-on assemblyassembly

– Support team based interactionSupport team based interaction

Capturing the Physical Capturing the Physical ModelModel

ScanningScanning Define color markersDefine color markers

Interaction in ME

Reconstruction from Reconstruction from multiple scansmultiple scans

Skill SetSkill Set ““Oh I don’t want to program, I just want to create Oh I don’t want to program, I just want to create

stuff”stuff” Architect or Car analogyArchitect or Car analogy Programming -> tool to create what is in your Programming -> tool to create what is in your

imaginationimagination Programming proficiency goal:Programming proficiency goal: be able to be able to

code anything that you imaginecode anything that you imagine To do what you saw before we use:To do what you saw before we use:

– C/C++, OpenGL, many different librariesC/C++, OpenGL, many different libraries Math, math, and yet more math!!!Math, math, and yet more math!!!

– Differential equations (simulations, physics engines), Differential equations (simulations, physics engines), linear algebra (transforms, 3D manipulations), statisticslinear algebra (transforms, 3D manipulations), statistics

Graduate SchoolGraduate School Programming Team Lead at RockStar GamesProgramming Team Lead at RockStar Games

– Worked on Midnight Club 2Worked on Midnight Club 2 Renderman Developer at PixarRenderman Developer at Pixar

– Worked on the Jellyfish of Nemo and The IncrediblesWorked on the Jellyfish of Nemo and The Incredibles Software Engineer for Interactive Media for DisneySoftware Engineer for Interactive Media for Disney

– Worked on Toon Town, online capable titlesWorked on Toon Town, online capable titles Worked at 989 Sports, EA Sports, Freedom Force, etc.Worked at 989 Sports, EA Sports, Freedom Force, etc. What did they all have in common?What did they all have in common?

– Published scientific journals in computer sciencePublished scientific journals in computer science– Graduate school in computer scienceGraduate school in computer science– Worked on efficient collision detection, particle systems, Worked on efficient collision detection, particle systems,

curved surfaces, virtual reality, etc.curved surfaces, virtual reality, etc.– All had All had

GRE scores in the top 10%GRE scores in the top 10% Went to a top graduate school (admission is tough)Went to a top graduate school (admission is tough) Strong math and science and coding Strong math and science and coding Why would a CS professor want to work with you?Why would a CS professor want to work with you?

Interested? Take the Interested? Take the following…following…

CAP4730 Computational Structures in CAP4730 Computational Structures in Computer Graphics (Fall ’05)Computer Graphics (Fall ’05)

CAP4930/6930 Design and Creation of CAP4930/6930 Design and Creation of Virtual Environments (Fall ’05)Virtual Environments (Fall ’05)

CAP4930/6930 Human-Computer CAP4930/6930 Human-Computer Interaction (Spring ’06?)Interaction (Spring ’06?)

Computational Geometry (Spring ’06)?Computational Geometry (Spring ’06)? Computer Simulation Concepts (Fall ’05)Computer Simulation Concepts (Fall ’05)

Virtual Experiences GroupVirtual Experiences Group PhD Students (4)PhD Students (4)– Kyle JohnsenKyle Johnsen– John QuarrelsJohn Quarrels– Andrew RaijAndrew Raij– Xiyong WangXiyong Wang

Undergraduates (4)Undergraduates (4)– Robert DickersonRobert Dickerson– Sayed HashimiSayed Hashimi– Andrew JoubertAndrew Joubert– Art HomsArt Homs

Alumni (4)Alumni (4)– Cyrus Harrison (MS)Cyrus Harrison (MS)– George Mora (MS) George Mora (MS) – Andrew Joubert (BS)Andrew Joubert (BS)– Samuel Preston (BS)Samuel Preston (BS)– John Samuelsen (BS)John Samuelsen (BS)

Thank you! Questions?