Josh Stephens Comp 6620. Characteristics Degrees of Freedom: particular, independent way that a body...

Josh StephensComp 6620

CharacteristicsDegrees of Freedom: particular, independent

way that a body moves in spaceInput type/Frequency of data:

Discrete: single data value (e.g. Boolean value)Continuous: generate multiple data valuse (e.g.

pixel coordinates)How much physical interaction is required.

Purely active: require user to perform some form of physical activity

Purely passive: does not require physical activity, continues to operate even when untouched

Intended Use: position/orientation information, produce real number values, indicate element of a set

CategoriesDesktop input devicesTracking devices3d miceSpecial purpose input devicesDirect human input

Desktop Input DevicesKeyboards2d mice and trackballsPen-based tabletsJoysticks6-DOF devices for desktop

KeyboardsTraditional desktop input deviceDiscreteChord keyboard

Held in one handUser presses combinations of keys for a single

alphanumeric input

Chord Keyboard

2d Mice and trackballsMade popular by WIMP interface design2 components:

Manually continuous 2d locator for positioning a cursor and generating 2d pixel coordinates

Set of discrete componentsRelative devices: report how far they have

moved rather than where they areTrackball more feasible for 3d environments

Pen-Based TabletsSame as mice and trackballs, except with the

addition of a manually continuous componentUse of a stylus to generate 2d coordinates“pen and paper” interface

JoysticksTraditionally used on desktopCombination of manually continuous 2d

locator and a set of discrete componentsIsotonic Joystick: Cursor typically continues

moving in the direction the joystick is pointing

Isoteric Joystick: large spring constant so they cannot be perceptibly moved. Output varies with the force the user applies to the device

6 DOF Input DevicesMove objects

dynamically in 3 dimensions

Useful in manipulating virtual objects

Tracking devicesMotion trackersEye trackersData gloves

Motion TrackingMagnetic trackingMechanical trackingAcoustic trackingInertial trackingOptical trackingHybrid tracking

Eye TrackingPurely passive input

devices used to determine where the user is looking

Uses corneal reflections detected by a camera

Electro-oculography: measures the skin’s electric potential differences using electrodes placed around the eye

Data glovesBend sensing gloves:

detect hand postures

Pinch Gloves: determines if a user is touching 2 or more fingertips together

3D MiceUser physically moves them in 3d spaceHandheld

Place motion trackers inside a structurehttp://www.youtube.com/watch?v=R-TBi3EfvE

UUser Worn

Makes the device an extension of they user’s hand

http://www.youtube.com/watch?v=fMeLZ8mAY5g

Direct Human InputObtain data directly from signals generated

by the human body.User becomes the input device.http://www.youtube.com/watch?v=QIqNdMq

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