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Introduction to Introduction to Virtual EnvironmentsVirtual Environments

CISE 6930/4930CISE 6930/4930

Benjamin LokBenjamin Lok

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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 factExample VRAMExample VRAM

Reality –Reality –the state or quality of being real. Something that the state or quality of being real. Something that exists independently of ideas concerning it. exists independently of ideas concerning it. Something that constitutes a real or actual thing as Something that constitutes a real or actual thing as distinguished from something that is merely distinguished from something that is merely apparent.”apparent.”

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

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

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ProgressionProgression

Story tellingStory telling What did this rely on? What did this rely on?

User’s imagination!User’s imagination!

Multi-sensoryMulti-sensory ImagesImages SoundsSounds

ControlControl EventsEvents ViewView

What do these things have in common?What do these things have in common? ImmersionImmersion

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Define VRDefine VR

Burdea:Burdea:

Virtual reality is a high-end user-computer Virtual reality is a high-end user-computer interface that involves real-time simulation interface that involves real-time simulation and interactions through multiple sensorial and interactions through multiple sensorial channels. These sensorial modalities are channels. These sensorial modalities are visual, auditory, tactile, smell, and taste.visual, auditory, tactile, smell, and taste.

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Burdea’s 3 I’s of VRBurdea’s 3 I’s of VR

Interactivity – user impacts worldInteractivity – user impacts world DefineDefine ChannelsChannels

Immersion – believing you are thereImmersion – believing you are there DefineDefine What contributes to it?What contributes to it?

Imagination – user ‘buying’ into the experienceImagination – user ‘buying’ into the experience Examples Examples Why is this necessary?Why is this necessary?

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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.”

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Our definition (from Brooks’ What’s Our definition (from Brooks’ What’s Real About Virtual Reality)Real About Virtual Reality)

Virtual Reality Experience – the user is Virtual Reality Experience – the user is effectively immersed in a responsive virtual effectively immersed in a responsive virtual world.world.

Implies -> user dynamic control of viewpointImplies -> user dynamic control of viewpoint

Control becomes an important element of VR Control becomes an important element of VR systems.systems. Differentiates VR from books and movies (or watching Differentiates VR from books and movies (or watching

movies in HMD)movies in HMD) Why is control more important?Why is control more important?

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Key Elements of Virtual Reality Key Elements of Virtual Reality ExperienceExperience

Virtual World - content of a given mediumVirtual World - content of a given medium 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 disbeliefmental immersion – suspension of disbelief physical immersion – bodily entering the physical immersion – bodily entering the

mediummedium Related to Related to presencepresence – (mentally immersed) – (mentally immersed)

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

Walking Experiment atUNC – Chapel Hill

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Key Elements of Virtual Reality Key Elements of Virtual Reality ExperienceExperience

Sensory Feedback – information about the Sensory Feedback – information about the virtual world is presented to the participant’s virtual world is presented to the participant’s sensessenses

Visual (most common)Visual (most common) AudioAudio TouchTouch

Interactivity – the virtual world responds to the Interactivity – the virtual world responds to the user’s actions.user’s actions.

Computer makes this possibleComputer makes this possible Real-timeReal-time

Walking Experiment atUNC – Chapel Hill

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Given these points… are these VR Given these points… are these VR experiences?experiences?

Virtual WorldVirtual WorldImmersionImmersionSensory FeedbackSensory FeedbackInteractivityInteractivityCreate a table and decide how these items stack up as Create a table and decide how these items stack up as VR or not:VR or not:

ZORKZORK Choose Your Own AdventureChoose Your Own Adventure Quake 3Quake 3 Shrek (The movie)Shrek (The movie) 747 Flight Simulator747 Flight Simulator Microsoft Flight Simulator 2004 (on a PC)Microsoft Flight Simulator 2004 (on a PC) Where the Red Fern GrowsWhere the Red Fern Grows

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Other Definitions (from book)Other Definitions (from book)

Artificial Reality Artificial Reality – synthetic environments in – synthetic environments in which a user may interactively participatewhich a user may interactively participateVirtual Virtual – not real. representations of physical – not real. representations of physical objects.objects.Virtual World, Virtual Reality, Virtual Virtual World, Virtual Reality, Virtual EnvironmentsEnvironments – used interchangeably. – used interchangeably. Brooks – we aren’t even close to creating realities yet.Brooks – we aren’t even close to creating realities yet.

Cyberspace Cyberspace – location that exists only in the – location that exists only in the mind of the participants. DO NOT OVERUSE or mind of the participants. DO NOT OVERUSE or lower letter grades will result! (kidding)lower letter grades will result! (kidding)

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Virtual EnvironmentsVirtual Environments

Augmented Reality (Mixed Reality)Augmented Reality (Mixed Reality)

TelepresenceTelepresence

Artificial RealityArtificial Reality

Classical Simulation EnvironmentsClassical Simulation Environments

Virtual RealityVirtual Reality

All Virtual Objects All Real Objects

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Augmented RealityAugmented Reality

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

Ultrasound Visualization Research atUNC – Chapel Hill

All Virtual Objects All Real Objects

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TelepresenceTelepresence

The use of various technologies to The use of various technologies to produce the effect of placing the user in produce the effect of placing the user in another location.another location.

All Virtual Objects All Real Objects

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Artificial Reality Artificial Reality (Myron Kruger)(Myron Kruger)

Responsive EnvironmentResponsive Environment

Is an environment where Is an environment where human behavior is human behavior is perceived by a computer perceived by a computer which interprets what it which interprets what it observes and responds observes and responds through intelligent visual through intelligent visual and auditory displaysand auditory displays

All Virtual Objects All Real Objects

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Classical SimulationClassical Simulation

Classical simulation is a mix of real objects and Classical simulation is a mix of real objects and computer generated stimuli.computer generated stimuli.

All Virtual Objects All Real Objects

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Virtual RealityVirtual Reality

Ideal for VR is that Ideal for VR is that everything you everything you experience is experience is computer-generated.computer-generated.

All Virtual Objects All Real Objects

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VR usually implies VR usually implies

Immersive TechnologyImmersive Technology Remember definitionRemember definition

Real-time first person viewReal-time first person view

Environment responds to you (at least at Environment responds to you (at least at the level of head-motion)the level of head-motion)

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Immersive TechnologyImmersive TechnologyHead-mounted Head-mounted DisplayDisplay Optical SystemOptical System Image Source (CRT or Image Source (CRT or

LCD)LCD) Mounting ApparatusMounting Apparatus EarphonesEarphones Position TrackerPosition Tracker

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Immersive TechnologyImmersive Technology

Multi-screen Projection of Multi-screen Projection of stereoscopic images stereoscopic images (CAVE)(CAVE)

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Immersive TechnologyImmersive Technology

Single large Single large stereoscopic displaystereoscopic display Projection-basedProjection-based Head-trackedHead-tracked Possible tracking of Possible tracking of

hands and arms.hands and arms. Brings virtual objects Brings virtual objects

into the physical worldinto the physical world

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Other CharacteristicsOther Characteristics

Head and body tracking implies that visual Head and body tracking implies that visual content is always computed and rendered content is always computed and rendered in “real time” (10-60 frames/second).in “real time” (10-60 frames/second).

In virtual reality you have a sense of, and In virtual reality you have a sense of, and interact with, three-dimensional things as interact with, three-dimensional things as opposed to pictures or movies of things.opposed to pictures or movies of things.

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What are the primary intellectual components What are the primary intellectual components that create a virtual environment?that create a virtual environment?

Hardware / TechnologyHardware / Technology

User’s Perspective (the environment that User’s Perspective (the environment that is experienced)is experienced)

System Software DesignSystem Software Design

Interaction TechniquesInteraction Techniques

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User’s perspectiveUser’s perspective

SettingSetting

Objects in worldObjects in world

Other participantsOther participants

Active/PassiveActive/Passive Factory SimulationFactory Simulation Architectural Architectural

WalkthroughWalkthrough

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Hardware / TechnologyHardware / Technology

What is my computation What is my computation environment?environment?

How many active users How many active users do I wish to do I wish to accommodate?accommodate?

What display modalities and technologies will What display modalities and technologies will I use?I use?

What sensor modalities and technologies will What sensor modalities and technologies will I use?I use?

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System Software DesignSystem Software Design

Software structures that run the virtual Software structures that run the virtual environmentenvironment Rendering groupRendering group

Graphics, audio, hapticGraphics, audio, haptic Sensor polling groupSensor polling group

Separately poll each sensor hardware subsystemSeparately poll each sensor hardware subsystem Computation groupComputation group

Manage the state of the environmentManage the state of the environment

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Interaction TechniquesInteraction Techniques

Do I interact with the Do I interact with the environment?environment?

How do I interact with How do I interact with the environment?the environment?

Not the same as what Not the same as what devices I usedevices I use

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Applications?Applications?

Most current applications:Most current applications:

Special PurposeSpecial Purpose

Interaction simple and/or infrequentInteraction simple and/or infrequent

Sidestep limitations of graphics and Sidestep limitations of graphics and hapticshaptics

A few expensive systems are sold to a few A few expensive systems are sold to a few rich peoplerich people

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EntertainmentEntertainment

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Design VisualizationDesign Visualization

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Training (NASA)Training (NASA)

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Clinical Virtual RealityClinical Virtual Reality

The direct use of VR as a tool in the treatment or The direct use of VR as a tool in the treatment or assessment of psychological and physical assessment of psychological and physical

disorders.disorders.

Hunter HoffmanHITLab – University of Washington

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Why VR?Why VR?

In groups – develop a In groups – develop a set of guidelines for set of guidelines for when to apply VR to a when to apply VR to a problemproblem

Give three examples Give three examples of applications that fit of applications that fit your definition, and your definition, and three examples of three examples of common common misconceptions.misconceptions.