Virtual Reality

Lecture2. Some VR Systems & Applications

고려대학교 그래픽스 연구실

Contents

• Graphical Input Devices• Some VR Systems• VR Applications• Problems

Graphical Input Devices

• Logical Input Devices

• 3D Input Devices

Logical Input Device Types

• Choice• Keyboard• Valuators• Locators

Choice

• Return a choice that has been made

• Examples : function keypad, button box, foot switch

• Often provide sensorial feedback : lights, clicks, feel,…

Button Box

Keyboard

• Returns keys with specific meanings• Letters, numbers, etc.

Valuators

• Returns a value for something• Example : knobs• Can usually specify gain, minimum, and

maximum• All locators can also double as valuators

Dial Box

Locators

• Return the location of the screen cursor• Examples : mouse, tablet, trackball, touchscre

en• Display-to-Input ratio

Locator Display-to-Input Ratio

• DTI Ratio : the amount of cursor movement on the screen divided by the amount of hand movement

• Large : good for speed• Small: Good for accuracy

Ways to Read an Input Device

• Sampling : What is its input right now?

• Event-based : Wait until the user does something

3D Input Devices

• Read a 3D position

• Return 3 numbers to the program : an (x,y,z) triple

• Some also return 3 more numbers to the program : three rotation angles

• Examples : digitizer, space ball, glove

3D Input Devices

3D Input Devices

Force Feedback in 3D

Force Feedback in 3D

Force Feedback in 2D

Some VR Systems

• Stereo Viewing• Shutter Glasses• Head Mounted Display• Head Tracking• Hand Tracking

Stereo Viewing

• Using Stereoscopic 3D perception• Measure the difference in angle from

each eye to the object • And, compute the distance to the object

( by an extremely sophisticated image processor in our brain )

Stereo Viewing

A stereo pair of Images

Head Mounted Display

• Use a separate monitor for each eye• Mounting small monitors in some sort of

head gear• Not VR yet by itself !!

Head Mounted Display

Head Tracking

• How the computer sense the position and orientation of your head in real time?

• Sense and record the position and orientation of each of the sensor

• Minimum capabilities to be called VR!

Head Tracking

Hand Tracking

• Finger actions could be used to control a program, just like a mouse of joystick …

• Ex) pushing virtual menu button, grabbing an object …

• Use a dataglove

Hand Tracking

Force Feedback

• Haptic feedback– Feeling the virtual world, not only viewing and inter

act thru hand motions..

• Haptic feedback glove– Use Hand actuators that could push back at you

Force Feedback

The CAVE

• Cave Automatic Virtual Environment

• Siggraph 92 Exibition

• Not a HMD, but a room where output of computer displays is projected onto the walls

• Projected images are in stereo by rapidly alternating between the two eye images for 3D effect ( A user wears a pair of stereo shutter glasses )

Some VR Applications

• Entertainment• Augmented Reality• Training• Remote Robotics• Distributed collaboration• Visualization

Entertainment

• Definitely the biggest market• The main force for driving down prices

on VR hardware• Ex) Game with other computers /

players

Entertainment

VR Gaming

Augmented Reality

• Bridging Virtual Environment and Real World

RealEnvironment

VirtualEnvironment

Augmented Reality

AugmentedVirtuality

Augmented Reality

Ultra sound Application

Virtual Surgery

Augmented Reality

Agent augmented realitylocation-aware interactive navigation/guidance system

Training

• When the cost of a mistake in Real Reality is very high

• Ex) Aircraft simulators, Train pilot training systems, Surgery simulator

Training

Flight simulator

Remote Robotics

Distributed collaboration

• More collaborative than by telephone or video conferencing

Virtual Conferencing

Distributed collaboration

Virtual Battles Collaborative Design

Visualization

• VR as a visualization research tool

Anyone in the room not wearing a display would not be

able to see the model at all

Problems

• Cost

• What’s it Good for?– None of the existing systems can solve

common everyday problems

• Display Resolution

• Update Speed