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Applications

Ruth Aylett

Overview

Buildings– Architecture and interior design– Urban planning– Virtual heritage

Medical simulation Scientific visualisation Entertainment

(UK VR Forum survey, 2000)

VR penetration in non-medical fields VR penetration in non-medical fields

% - companies using,% - companies using, Experimenting or Experimenting or Considering VR Considering VR

Classes of VR applicationsClasses of VR applications

(UK VR Forum survey, 2000)

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Main benefits of using VRMain benefits of using VR

(UK VR Forum survey, 2000)

Barriers to VE application

Limited understanding of VEs– Need for trained developers

VE development is challenging VE Application development requires a range

of skills– Hardware, software and design

Lack of off-the-shelf VE applications Cost considerations Lack of standards

Architecture and interiordesign

Possibly the first application area– Takes advantage of ability to change

textures, furnishings, layout Issues

– Need for (semi-)automated modelling– How can models be archived?– Collaborative viewing often required

Virtual heritage

Replicas of famous archeological, architectural andnatural site– In 2000 the Virtual Heritage Network (www.virtualheritage.net)

formed as UNESCO affiliate. Recreation of a virtual heritage model starts with

architectural plans, historical documents and visit to theactual site to acquire photos (used later for textures).

Light measurements need to be made for input toradiosity computations.

Care for cultural sensitivities, as models are placedonline..

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Created by a group at University of Geneva;

Consists of a 18,000 polygon exterior model and a 59,000 polygoninterior model created using 3D Studio Max; Uses light maps.

Virtual Heritage Virtual Heritage –– SS SS Sergius Sergius and and Bachus Bachus ((IstambulIstambul))

Model viewed in VRML 97Model viewed in VRML 97

The VRML viewer assured 30 frames/sec with 2-cm geometricalaccuracy; A custom VRML extension (to allow multi-texturing) was subsequentlyused to increase realism, but frame rate dropped to 10-26 fps.

Virtual Heritage Virtual Heritage –– SS SS Sergius Sergius and and Bachus Bachus ((IstambulIstambul))

Custom VRML 97Custom VRML 97

VirtualNotre Dame –the bestknown churchin Europetook 200years tocomplete. Modeledusing the EpicUnreal engine(normallyused in gamecreation).

Virtual HeritageVirtual Heritage

Virtual tours with a guide who is a friar (1200 textured polygons).Had predetermined motion sequences. An AI engine (well, an FSM) drives his behavior, based on inputfrom proximity sensors placed at various locations inside the virtualcathedral

Virtual Notre Dame Virtual Notre Dame

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What are the issues? Acquiring models

– Often very intricate: hand builds very expensive– Need for automation

Modelling accuracy– Curators are very keen on this– Getting the geometry and textures right is hard– Use of rangefinders for carved surfaces

Need for high-resolution displays– Brilliant model on a poor display?

The business model is opaque– Doing it well is expensive but heritage organisations usually

lack money

VR-based training

Why medical simulations?

To train and certify medical personnel To reduce the use of animals in training To test new surgical devices and

procedures

Simulation of MIS

procedures

TissueMechanics

DeviceDesign

TrainingTransfer

Real-timeInteraction

Overview Sample systemHaptic Displays

VisualDisplay

LaparoscopicInstruments

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Challenges:

• membrane+bending elements• 6-dof for each node• Stiffness Matrix : K (600x600), diagonal M and C

600 coupled equations !

Real-time Display

• Graphics (30 Hz) • Haptics (1000 Hz)

1 msec !

Tissue Characteristics

• nonlinear• anisotropic• hysteresis• non-homogeneous

Deformation

Force on thetool

Tissue/organ model

Loadingvia tool

Physically-Based Modeling

. . . F = MU + CU + KU(dynamic analysis)

complex !

F: force

FEM ?

Node (e.g.100)

Tissue/organmodel

Key topics

A) Collision detection and computationalmodels of surgical instruments

B) Physically-based modeling for simulatingsoft tissue behavior

C) Haptic rendering of deformable objects

D) Software and hardware integration

Cyctic DuctCatheter

LaparoscopicForceps

What you see ... What is really happening ...

Line Segments

Particles

Polyhedron

Simulation of Catheter Insertion into the Cyctic Duct

An example Computational Models ofLaparoscopic Instruments

Group A Group B

Ray-based renderingPoint-based rendering

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Simulation of Catheter Insertion

Simulation Set-Up

Real

Virtual

Virtual

Geometric Model

VR Therapy

Exposure desensitisationtreatment– effective for a wide range

of phobias– Spiders, airplanes,

heights, storms– Social phobias:

audiences

Post Traumatic Stress Disorder Treatment Environment

See http://www.virtuallybetter.com/

Virtual Vietnam

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Scientific Visualization vs. Data Visualization● Scientific Visualization:

● graphical representations from the results ofmathematical models, computations andsimulations

● Involves research in computer graphics, imageprocessing, high performance computing, and otherareas

● It's not just a pretty picture or animation

● Data Visualization:● More general term● Implies treatment of data source beyond science and

engineering, such as financial, business data, etc.

Visualization is not only looking into a prettypicture…– understanding of the data– been able to analyze and interpret data

Spot Noisehttp://www.llnl.gov/graphics/spot.html

Applications

Used in:

– Engineering– Computational Fluid

Dynamics– Simulation– Medical Imaging– Geospatial– Ground Water Modeling– Oil and Gas Exploration

and Production– and more…

Concepts associated with Visualisation

Personal visualisation:analyze results, graphics in yourPC.

High-resolution displays:visualisation of large-data sets.

Immersive visualisation: anenvironment where the user isimmersed in the computergenerated 3D graphics.

Collaborative visualisation:two or more users visualise thesame data using differentdisplays.

Visualisation examples

Amira– Merger of binary orbiting neutron stars– General relativistic simulation of

gravitational energy

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Earthscience visualisation

Good understanding of spatial relationshipsfundamental to the study of Earth Sciences.

Traditional teaching relied on 2D representations– maps and profiles– augmented by physical models.

Can extract 3D structure from such representations– But requires specialised spatial thinking skills– difficult to learn– a stumbling block for students at the introductory level.

GeoWall

Aims to broaden the use of scientificvisualization tools for Earth Science– using low cost virtual reality visualization

devices.– Current GeoWall hardware is based on

Agave technology developed at theElectronic Visualization Lab, University ofIllinois

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Software & Hardware Needed

Software – image display for GeoWall OpenGL base, stereo pair, vpokescope,

viewer, wallview Software – geometry display 2Space assistant, coanim, iView 3D etc Hardware – Projectors, Screens, Linear

Polarization Glases, Circular Polarization,Projector Stackers, Graphics Boards andStereo Cameras

Vis5D - Weather

Interactive visualization of large 5-D griddeddata sets such as those produced bynumerical weather models.– Can create isosurfaces, contour line slices, colored

slices, volume renderings, etc of data in a 3-Dgrid,

– rotate and animate the images in real time.– Feature for wind trajectory tracing– support for text annotations for publications,– support for interactive data analysis, etc.

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FieldView – Fluid Dynamics

FieldView is the World's Leading Post-processing and Visualization forComputational Fluid Dynamics

Velocityprofile withinan EngineBlock

One of a series of images used by LockheedMartin at the 1997 Paris Air Show. Ananimation was created with FieldView, andprojected onto a scale model of an F22 aircraft.

Pressure contours and velocity vectors on anF18. - Data courtesy Nasa Langley ResearchCenter

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References

www.ssec.wisc.edu/~billh/vis5d.html www.amiravis.com www.sgi.com www.ilight.com www.geowall.org

Visualisation issues

Photo-realism is NOT an issue typically– What to visualise how must be thought out– Use of sound and colour may help

• Bright colours = close?• High sounds = small-scale?

Interaction technologies typically lessimportant– Usually straight navigation will do– Plus some zoom in and out

VR in manufacturing Disney has constructed Disney Quest – a building full of arcades; Allow feedback effects not possible at home, and multiplayergames. An example – “Pirates of the Caribbean” – motion platform;Passive tactile feedback, stereo graphics (SGI);

VR Entertainment ApplicationsVR Entertainment Applications

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Disney also developed the “Virtual Jungle Cruise” on inflatablerafts. Pneumatic motion platform, sensorized oars and water spraysadd to the feeling of immersion.

VR Entertainment ApplicationsVR Entertainment Applications

JumpZone – single playerarcade – parachute jump; HMD, harness, fan,sensorized ropes

VR Entertainment ApplicationsVR Entertainment Applications

JumpZone – theme park concept

VR Entertainment ApplicationsVR Entertainment Applications

Courtesy of Illusion Systems

Issues

It really does have to be robust– Large numbers and long periods of use– Minimal technical support available

Big constraints on interaction devices– Robustness, ease of use, very intuitive

• See Disney specialised devices

Very large scale integrated systems– Big displays

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Conclusions

Applications in wild variety Basic modelling becoming increasingly widely

used– Urban planning etc

Industrially oil/gas have pioneered technology– Large-scale visualisation applications

Potential in concurrent engineering– Still low uptake