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Explore the historical evolution of graphics hardware from Ivan Sutherland’s pioneering work in 1968 to the current state-of-the-art systems in 2008, assessing advancements in head-mounted displays, image generation, and head tracking technologies.
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Evolution of Graphics Hardware:40 years since Sutherland’s HMD • Henry FUCHS • University of North Carolina at Chapel Hill • Graphics Hardware 2008 Sarajevo
AcknowledgementAssistance with preparation of this talk • Hideyuki Tamura, Canon • Greg Welch, UNC • Mark Mine, Disney • Steve Molnar, NVIDIA • Adam Lake, Intel
Evolution of Graphics H/W: from what point ? • Ivan Sutherland’s 1963 PhD Sketchpad • Beginning of graphics, but no new hardware • Sutherland’s 1965 “Ultimate Display” idea • A vision, but no specific HW specified • Sutherland’s 1968 3D HMD System • Complete working system, needed all specialized HW
Ivan E. SutherlandA Head-Mounted Three-Dimensional Display,1968 Fall Joint Computer Conference • Implemented all the components of a real-time interactive 3D graphics system: • Display device: stereo, optical see-through • Image generation: Real-time 3D perspective • Head tracking: Real-time 6 DOF • 3D model creation • Hand-tracking & interaction: Real-time 3 DOF (’69 ?)
Procedure for Examining Evolution of Graphics HW • For each subsystem: display, image generation, tracking.. • 1968: what was implemented, state of the art • ~1988: sample state of the art • 2008: current example subsystem • Assessment: • The dream in 1968/1970 • Grade for where we are now: A, B, C, D
Display device on ’68 HMD • Optical see-through head-mounted display
HMD ca. 1985: VPL head-mount • Closed display, not see-through • LCD from SONY pocket TV • wide angle optics (LEEP) • (no distortion correction)
HMD ca. 1995: video see-through HMD (UNC) • Need for video, rather than optical, see-through
Current HM Displays • closed, total VR • Fakespace wide5 • Video see-through: • Canon / Mixed Reality Labs VH2002 • InnerOptic (based on UNC design)
Assessment on HM Displays • The dream at 1968 / 1970: Displays built in to our ordinary eyeglasses; see virtual objects throughout the eyeglass lenses (not a ‘virtual inset’) • Grade for where we are now: C • significant progress • not even close to adequate
Image generation:Sutherland’s 1968 system • Real time • Line drawing • No hidden line elimination • Heroic work: everything built out of gate-level chips • 3D transforms • Clipping divider • Graphics pipeline
Image generation: ca 1988 • Real-time full-color raster image generation • Rapid, consistent progress throughout the 1980s and 1990s • 100s of polygons /sec in 1980 • Million polygons / sec early 1990s • UNC Pixel-Planes 5 at siggraph 1991: 2M polygons/sec
Image generation now • Sophisticated shading effects and millions of polygons /sec • Commodity graphics chips & boards • Rapid, continuing progress • Image generation processors becoming ubiquitous –migrating even to mobile devices
Image Generation Assessment • Dream of 1968/1970: Realistic image generation • Sutherland 1965 Ultimate display: can’t distinguish between virtual and real objects • Grade for where we are now: • A+ • Are we finished? • No! illuminate globally; integrate physics sim. with graphics; integrate image capture with image display,.. • Feels great for the field to be doing so well.
Head tracking: Sutherland’s 1968 system • Two tracking systems implemented • ultrasound tracking with multiple emitters and receivers • mechanical tracker
Head tracking (ultrasonic)Sutherland’s 1968 system • Ultrasonic tracking • 3 transmitters on head-mount • 4 receivers hanging from ceiling • Measure phase changes • Problem with ambiguity of number of cycles of u/s signals • Problem exacerbated by heating system
Head tracking (mechanical)Sutherland’s 1968 system • Vertical pivot in ceiling • Universal joint on top • Universal joint on bottom • Shaft slides in and out • “Sword of Damocles” • Heavy and uncomfortable • Works
Head Tracking ~1988: Polhemus Magnetic Tracking • Developed for head tracking in cockpit • Very close range • Not for walking across a room • Severe warping of space with metal, with other magnetic fields. Can be reduced with calibration
Large area trackers: ~ 1991 UNC • 10x12 ft space demonstrated at Siggraph 1991 • Multiple optical sensors on head, LEDs in ceiling tiles • Lateral effect photo-diodes, much faster than imagers • One LED lighted at a time • Predict most-useful LED to light each time slot
Head tracking Now • Multiple good solutions • Optical • Magnetic • Inertial / optical combination • Limited to instrumented area
Head tracking assessment • Dream of 1968 / 1970: Go anywhere, unencumbered • Grade for where we are now: • B • Choice of solutions on the market if willing to live with restrictions • Degraded performance if lose line of sight contact (optical trackers) or near ferrous/metal objects (magnetic trackers) • Can’t go outside of instrumented area, nor outdoors. • Steady progress
Interaction / Hand tracking in Sutherland’s HMD • Mechanical design with three reels of fishing line mounted from ceiling • All lines connected to top of (camera) hand-grip • Amount of line reeled out determines 3D location of hand-grip • Problem of interference between head and hand trackers
Interaction / Hand tracking ca.1988 • Polhemus magnetic tracker (time-shared with a target for head-tracker) • VPL DataGlove sometimes added to hand-tracker • Severe warping of tracked space if user moves more than a few steps
Interaction / Hand tracking now • Multiple technologies available • Accuracy & speed may not be adequate for certain applications • UNC AR assistance for surgical needle guidance • Track ultrasound transducer • Track needle
Assessment of Hand tracking • Dream in 1968/ 1970: unencumbered tracking of hand • Grade for where we are now: • Incomplete • Haven’t had sufficient number of real applications to judge --- rest of system hasn’t been ready • using Fred Brooks’ denition of “What’s real about Virtual Reality?” • Someone other than develops pay to use the system
3D model creation • Sutherland’s 1968 system: trivially simple
3D model creation ca. 1988 • Manual model creation increasingly expensive / time-consuming with increasing capability of image generation systems • Feasible if 3D model needed to be created as part of the application itself: CAD/CAM, selected medical applications • Automatic scanning for selected objects: Cyberware 3D scanners
3D Model Creation Now • Growing list of commercial and research capabilities • Computer vision: multiple images / video to 3D world models • Laser scanners • Motion capture systems
Assessment of Model Creation • Dream in 1968 / 1970: • Sutherland: Building model may be as time-consuming as building the real thing • Others: There’s got to be an automatic way • Grade for where we are now • C+ • There are many tools and systems, but often still takes much tedious, manual effort • Compare how much more work to digitizing this room and its contents than to rendering it
Assessment Summary • Display: • perennially, next model will be really good C • Image generation: • unalloyed triumph! (but don’t let it go to your head) A+ • Head tracking: • effective but in limited, prepared spaces B • Interaction / Hand tracking: • awaiting more real applications Incomplete • Model generation: • frustratingly time-consuming C+
Opportunities: Look at larger picture than a single module • Head-mounted display design combined with image generation • Fakespace Wide5: hardware geometric distortion correction • Mark Mine (Disney) implementing more sophisticated version in GPU • Image generation combined with head-tracking • Model creation combined with image generation • System problem spread across multiple modules: • latency
Sutherland’s vision of the HMD as the penultimate display still inspires
In conclusion:Don’t constrain your dreams;there is so much cool graphics HW to invent • Stereo and autostereo displays • Multi-projector / camera systems • Vision capture for image-based rendering • Haptics in the small and large • Cell phones w/graphics & vision: magic lenses in the real world • Telepresence systems (could do an entire hour on this) • Finally– Alan KayThe best way to predict the future is to invent itTHE END 35