One or more buttons can be programmed to act as input switches. Potentiometers mounted at the base of the joystick measure the amount of the movement, and springs return the stick to the centre position when it is released. The distance that the stick is moved in any direction from its center position corresponds to screen-cursor movement in that direction. JoysticksĪ joystick consists of a small, vertical lever (called the stick) mounted on a based that is used to steer the screen cursor around. Spaceballs are used for 3D positioning and selection generations in virtual reality systems. Strain gauges measure the amount of pressure applied to the Spaceball to provide input for spatial positioning and orientation as the ball is pushed or pulled in various directions. While a trackball is a two-dimensional positioning device, a Spaceball provides six degrees of freedom. Track balls are often mounted on keyboards.
Potentiometers attached to the ball, measure the amount and direction of rotation. Trackball & SpaceballĪs the name implies, a trackball is a ball that can be rotated with the finger or palm of the hand, to produce screen-cursor movement. This design provides six degrees of freedom to select the object and to perform the actions. The Z-mouse includes three buttons, a thumbwheel on the side, a trackball on the top, and a standard mouse ball underneath. One, two or three buttons are usually included on top of the mouse for signaling the execution of some operation. Another method of detecting mouse motion is with an optical sensor. Wheels or rollers on the bottom of the mouse can be used to record the amount and direction of movement. MouseĪ mouse is a small hand-held device used to position the screen cursor. Additionally, a numeric keyboard is often included on the keyboard, for fast entry of numeric data. Function keys allow users to enter frequently used operations in a single keystroke, and cursor control keys can be used to select display objects or co-ordinate positioning devices. Keyboards can also be provided with features to facilitate entry of screen co-ordinates, menu selections or graphics functions.Ĭursor-control keys and functions keys are common features of general purpose keyboards.
The keyboard is an efficient device for inputting such non-graphic data as picture labels associated with a graphics display. KeyboardsĪn alphanumeric keyboard on a graphics system is used primarily as a device for entering text strings. Most systems have a keyboard and one or more additional devices specially designed for interactive input. Various devices are available for data input on graphics workstations.
0 kommentar(er)
