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Spatially Immersive Visualization Systems

(an update)

Prof. Frederic I. ParkeVisualization Sciences

Texas A&M University

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Project History

~1990 Air Force project @ NYIT ~1998 current concept (w/Ergun) 2000 CRIC funding (~$5k) 2002 TITF funding ($165k) 2005 NSF MRI funding ($500k)

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Spatially Immersive Systems

Multiple images projected on surrounding surfaces

Often use stereo images – (active) Sequential images– (passive) Dual stereo images

Provide interaction modes May use position tracking

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Example -‘Cave’ Systems

up to 6 surfaces of a small room or cubical environment

typically systems use only 3 or 4 walls

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Immersive Environments

Major Components

– the computational “fabric”

– the display “surfaces”

– user interaction and tracking

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Visual Computing Clusters

Extended Cluster Concept Use ‘visual’ computing nodes Each computational node has a

graphics processor Each node drives a small ‘facet’ of the

total display surface

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Related Prior Work

Tiled Displays/PowerWalls– Princeton– Argonne National Lab– UNC-CH

Multi-Graphics Project– Stanford

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What’s the ‘Ideal’ Display Surface?

Is probably task specific One concept is a seamless surrounding

sphere with high resolution wrap around dynamic images, high update rate, and high complexity modeled environments

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Display Geometries

We want better geometric approximations

to the ‘ideal’ sphere

The CAVE is a poor approximation

A number of polyhedron configurations are better

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Polyhedron Display Systems

Multiple display facets Each facet driven from one (or two)

visual computing node Low cost per facet High aggregate performance High aggregate resolution

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Our configuration of interesta 24 facet polyhedron

Trapezoidal Icositetrahedra

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24 Facet polyhedron as approximation to a sphere

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24 Facet projector placement

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Simulated cross-sectional view of a

5 meter 24 facet display environment

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Another possible configurationa 60 faceted polyhedra

Pentagonal Hexcontahedra

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Our objectives

Useful and effective Integration into ‘workflows’ ‘Low’ cost Commodity components Reasonable performance

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Challenges

Software Development/Integration Distributed Data Management Workflow Integration Display Synchronization / Stereo Display Physical Structure/Environment Suitable Projection Systems Display Calibration

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Stereo Display

Passive anaglyphic – red /cyan (one proj)

polarization (two projectors)

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Physical Structures

Screen frame designMinimal ‘seams’

Projector placementOptical foldingProjector mountsHeat ‘ripples’

Screen materialsOptical properties

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Image Compensation

Geometric correction– off axis & projector distortion

– ‘Image stability’

– explored several approaches Intensity / color correction

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The Problem

Image alignment on individual projectorsWe Want… We Get…

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Basic Approach

Compute the correct image Use as texture on a poly mesh Pre-distort mesh to compensate for

geometric projection distortion

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GPU based solutions

Instead of relying on OpenGL default texturing, control the warping through the GPU

Create a 2D displacement texture Access the displacement texture to get

an offset, then access the image with the UV coordinates and the offset

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GPU based extensions

Color correctionEasy to hue/color shift texel values

Brightness correctionEasy to adjust the brightness of texelsIntensity falloff correction by altering

brightness based on a grayscale calibration image

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Structural Prototypes

We have developed a series of structural prototypes

We learned something from each!

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3/10 scale physical model using 24 identical facets

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3/10 ScalePrototype

Architecture Building Atrium

~ 5’ diameter

(Mid – 2001)

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¾ Scale Presentation Prototype

Completed May 2002

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Half of 24 facet structural frame

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Structure with projected images

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Series of Development Systems

3 screen prototypes3/4 scale and full scale

5 screen prototype (full scale)

7 screen prototype (1/2 scale)(Currently in development)

Software (two generations)‘3Dengine’ and ‘Guppy3D’

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Rear view of 4 screen structure section

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Initial 3 facet development system in use

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Alternative 3 Facet System

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Operational 5 Facet System

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Next – Two 7 Facet Systems

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Budget for each 7 Facet System

7 x $17.75k = ~$124k plus ~ $36k for a control/interface

computer, interaction devices, networking, sound, installation, etc…

Total ~ $160k

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Per Facet Budget (2005)

For each facet ~ $17.75k– 2 Visual computing nodes ~ $9k– 2 Display projectors ~ $3.5k– Screen and structure ~$3.8k– Misc. components ~$1.45k

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Application Projects

Architecture ‘Ranch’ Montezuma Castle A

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Architecture ‘Ranch’

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Architecture ‘Ranch’ on 3 facet system

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Architecture Ranch on the 5 facet system

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Montezuma Castle A

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Montezuma Castle A

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Montezuma Castle A

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