Interaction in Interaction in Virtual Virtual Environments Environments Benjamin Lok Benjamin Lok This Lecture contains notes This Lecture contains notes created by created by Doug Bowman Doug Bowman Virginia Tech Virginia Tech Sherman & Craig, pp. 332-363 Sherman & Craig, pp. 332-363
Interaction in Virtual Environments. Benjamin Lok. This Lecture contains notes created by Doug Bowman Virginia Tech Sherman & Craig, pp. 332-363. 3D Interfaces. We live in a 3D world Natural interfaces are better Therefore 3D interfaces will be the ultimate What’s wrong with the above? - PowerPoint PPT Presentation
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Interaction in Interaction in Virtual Virtual
EnvironmentsEnvironmentsBenjamin LokBenjamin Lok
This Lecture contains notes created This Lecture contains notes created by by Doug BowmanDoug BowmanVirginia TechVirginia TechSherman & Craig, pp. 332-363Sherman & Craig, pp. 332-363
3D 3D InterfacesInterfaces
We live in a 3D worldWe live in a 3D world Natural interfaces are betterNatural interfaces are better Therefore 3D interfaces will be the Therefore 3D interfaces will be the
ultimateultimate What’s wrong with the above?What’s wrong with the above?
3D Interfaces3D Interfaces What we really want are What we really want are enhancedenhanced interfaces interfaces
Give us powers we don’t Give us powers we don’t normally havenormally have Flying, x-ray vision, teleportation, Flying, x-ray vision, teleportation,
undo, etc.undo, etc. Be careful we don’t become Be careful we don’t become
overzealousoverzealous Air traffic control 3D displayAir traffic control 3D display Library interfaces using a books Library interfaces using a books
on shelves (what is it good for? on shelves (what is it good for? What is it poor for?)What is it poor for?)
Hurts performanceHurts performance Study results: Study results: 3D Bar charts 3D Bar charts
don’t help don’t help So what is helped by 3D?So what is helped by 3D?
Good 3DGood 3D Social interfaces + 3D can Social interfaces + 3D can
be very powerfulbe very powerful MMORPG (EveQuest)MMORPG (EveQuest) ActivedWorldsActivedWorlds The Sims OnlineThe Sims Online
ExperiencesExperiences Art gallaryArt gallary 3D Desktops (Mac’s latest)3D Desktops (Mac’s latest) Office metaphors did not Office metaphors did not
take off (BOB, Task Gallary)take off (BOB, Task Gallary) 3D Webbrowsing. Sure you 3D Webbrowsing. Sure you
can arrange 16 web pages can arrange 16 web pages spatially, but why?spatially, but why?
Compromises to provide Compromises to provide 3D interfaces might be 3D interfaces might be undermine usabilityundermine usability Think RTS gamesThink RTS games
Discussion: Is the interface Discussion: Is the interface holding back 3D?holding back 3D?
3D 3D InterfacesInterfaces
Use occlusion, shadows, perspective carefullyUse occlusion, shadows, perspective carefully Improves use of spatial memory (Ark ’98)Improves use of spatial memory (Ark ’98) Distracting and confusingDistracting and confusing
max)max) Simple user movement (why lock to a floor?) Simple user movement (why lock to a floor?)
Descent vs QuakeDescent vs Quake Prevent Errors (put in guides to help)Prevent Errors (put in guides to help) Simplify object movement (connecting two parts, Simplify object movement (connecting two parts,
for example, can be abstracted… most of the time)for example, can be abstracted… most of the time) Organize groups of items into alignments that Organize groups of items into alignments that
facilitate visual search and recall (allow user facilitate visual search and recall (allow user choice)choice)
3D Interface 3D Interface DevelopmentDevelopment
Developments that show promise:Developments that show promise: 3D sound3D sound Stereo display (Ware and Frank ’96)Stereo display (Ware and Frank ’96) Haptic feedback (mouse)Haptic feedback (mouse)
3D can help by:3D can help by: Provide overviews to see big pictureProvide overviews to see big picture Rapid teleportation (context shifts)Rapid teleportation (context shifts) Zooming (aid disabled)Zooming (aid disabled) Multiple coordinated views (3dsmax)Multiple coordinated views (3dsmax) 3D icons can represent abstract or recognizable 3D icons can represent abstract or recognizable
conceptsconcepts
TeleoperatioTeleoperationn Combines:Combines:
Direct ManipulationDirect Manipulation Process ControlProcess Control
Human operators control Human operators control physical processes in physical processes in complex environmentscomplex environments
Example applications: Example applications: Mars rover control, flying Mars rover control, flying airplanes (Predator), airplanes (Predator), manufacturing, medicine manufacturing, medicine (surgery)(surgery)
Supervisory control Supervisory control (Sheridan ’92)(Sheridan ’92) Different levels of human Different levels of human
control (automation)control (automation)
TeleoperatioTeleoperationn Direct Manipulation IssuesDirect Manipulation Issues
Best interaction?Best interaction? Flight simulators (they can cost $10 mil, but that’s still Flight simulators (they can cost $10 mil, but that’s still
a good deal!)a good deal!) Why?Why?
Why do video game flight sims not cut it? (only $40!)Why do video game flight sims not cut it? (only $40!) Okay, we have monitors that show 3D worlds, Okay, we have monitors that show 3D worlds,
what else do we possibly need?what else do we possibly need?
Why 3D interaction?Why 3D interaction? 3D / VE apps. should be useful3D / VE apps. should be useful
ImmersionImmersion Natural skillsNatural skills Immediacy of visualizationImmediacy of visualization
But, current VE apps are But, current VE apps are Not complex interactivelyNot complex interactively Have serious usability problemsHave serious usability problems
What makes 3D What makes 3D interaction difficult?interaction difficult?
Spatial inputSpatial input Lack of constraintsLack of constraints Lack of standardsLack of standards Lack of toolsLack of tools
Lack of precisionLack of precision FatigueFatigue Layout more complexLayout more complex PerceptionPerception
You’ve seen this in creating Project #2!
Let’s look at this example Let’s look at this example (ISAAC)(ISAAC)
techniques efficient for techniques efficient for relative motionrelative motion
Manipulation-based Manipulation-based techniques not requiring techniques not requiring an object efficient for an object efficient for search, but tiringsearch, but tiring
Steering techniques best Steering techniques best for naïve for naïve andand primed primed searchsearch
Map-based techniques Map-based techniques not effective in unfamiliar not effective in unfamiliar environments, or when environments, or when any precision is requiredany precision is required
MythsMyths
There is one optimal travel technique for VEs.There is one optimal travel technique for VEs. A “natural” technique will always be better A “natural” technique will always be better
than another technique.than another technique. Desktop 3D, workbench, and CAVE Desktop 3D, workbench, and CAVE
applications should use the same travel ITs applications should use the same travel ITs as HMD-based VEs.as HMD-based VEs.
Design guidelinesDesign guidelinesMake simple travel tasks simple (target-based Make simple travel tasks simple (target-based techniques for motion to an object, steering techniques for motion to an object, steering techniques for search).techniques for search).
Provide multiple travel techniques to support Provide multiple travel techniques to support different travel tasks in the same application.different travel tasks in the same application.
More design guidelinesMore design guidelines Use transitional motions if overall environment Use transitional motions if overall environment
context is important.context is important. Train users in sophisticated strategies to help Train users in sophisticated strategies to help
them acquire survey knowledge.them acquire survey knowledge. Consider integrated (“cross-task”) ITs if travel is Consider integrated (“cross-task”) ITs if travel is
used in the context of another task (e.g. used in the context of another task (e.g. manipulation).manipulation).
WayfindingWayfinding Cognitive process of Cognitive process of
defining a path through defining a path through an environment using and an environment using and acquiring spatial acquiring spatial knowledgeknowledge
6DOF makes wayfinding 6DOF makes wayfinding hardhard
Human beings have Human beings have different abilities to orient different abilities to orient themselves in an themselves in an environmentenvironment
Observing wayfinding as Observing wayfinding as a decision making a decision making processprocess
Wayfinding tasksWayfinding tasks General, explorative General, explorative
search search Search without Search without
targettarget NNaïaïveve search search
target position target position unkunknownnown
Primed searchPrimed searchtarget seen before target seen before
Cognitive MapCognitive MapDuring wayfinding, a During wayfinding, a person makes use of person makes use of three kinds of three kinds of knowledge to built up a knowledge to built up a cognitive map of the cognitive map of the environment:environment: Landmark knowledge Landmark knowledge Procedural knowledge Procedural knowledge Survey knowledgeSurvey knowledge
position, orientation, position, orientation, movement of object with movement of object with respect to position and respect to position and orientation of the:orientation of the: eyes eyes head head bodybody
Exocentric reference frame:Exocentric reference frame: position, orientation and position, orientation and movement are defined in movement are defined in coordinates external to bodycoordinates external to body object shapeobject shape object orientationobject orientation object motionobject motion
Travel technique effectsTravel technique effects Steering technique with Steering technique with
good strategy helps good strategy helps spatial orientationspatial orientation
A good travel technique A good travel technique will integrate aids to will integrate aids to wayfinding wayfinding
Jumping between points Jumping between points disturbs spatial disturbs spatial orientationorientation
Support of spatial Support of spatial knowledge acquisition knowledge acquisition
Allow a wide field of viewAllow a wide field of view Provide motion cues for Provide motion cues for
judging depth and judging depth and direction of movement direction of movement
Audio could enhance Audio could enhance visual spatial perceptionvisual spatial perception
Support sense of Support sense of presence: it could presence: it could strengthen the strengthen the construction of a construction of a cognicognitive maptive map
Support of spatial Support of spatial knowledge acquisitionknowledge acquisition
Design Design legiblelegible environments - allow the environments - allow the user to easily see the user to easily see the spatial organisation of an spatial organisation of an environment, enabling the environment, enabling the establishment of a establishment of a cognitive map. cognitive map.
Divide a large-scale Divide a large-scale environment into parts environment into parts with a distinct characterwith a distinct character
Support of spatial Support of spatial knowledge acquisitionknowledge acquisition
Create a simple spatial Create a simple spatial organisation in which the organisation in which the relations between the relations between the parts are clearparts are clear
Support the matching Support the matching process between the process between the egocentric and exocentric egocentric and exocentric frames of reference by frames of reference by (visual) cues, including (visual) cues, including directional cuesdirectional cues
Support of Spatial Support of Spatial KKnowledge Acquisitionnowledge Acquisition
Use real-world wayfinding Use real-world wayfinding principles to build up your principles to build up your environmentenvironment
Two Handed and Two Handed and Body-Centered Body-Centered
InteractionInteraction What can you do with two hands?What can you do with two hands? What if you use your body as a What if you use your body as a
reference point?reference point? Mine, Mark, Frederick P. Brooks Jr., and Carlo Sequin Mine, Mark, Frederick P. Brooks Jr., and Carlo Sequin
(1997). (1997). Moving Objects in Space: Exploiting Moving Objects in Space: Exploiting ProprioceptionProprioception in Virtual-Environment Interaction. in Virtual-Environment Interaction. Proceedings of Proceedings of SIGGRAPH 97, Los Angeles, CA. SIGGRAPH 97, Los Angeles, CA. (133K (133K pdfpdf version) version)
What can you do with What can you do with two hands?two hands?
What if you use your What if you use your body as a reference body as a reference point?point?
Mine, Mark, Frederick P. Brooks Jr., Mine, Mark, Frederick P. Brooks Jr., and Carlo Sequin (1997). and Carlo Sequin (1997). Moving Objects in Space: Exploiting Moving Objects in Space: Exploiting ProprioceptionProprioception in Virtual-Environment Interaction. in Virtual-Environment Interaction. Proceedings of SIGGRAPH 97, Los Proceedings of SIGGRAPH 97, Los Angeles, CA. Angeles, CA. (133K (133K pdfpdf version) version)
Two Handed and Two Handed and Body-Centered Body-Centered