Module 1 Flashcards
To draw an image, what do we start with?
Geometry
Conversion of a 3D scene to s 2D image
Rendering
Compute color of geometry
Shading
Project geometry
Projection
Clip geometry
Clipping
Generate fragments from geometry
Rasterization
Computer pixel colors from fragments
Fragment processing
The process by which color is assigned to geometry
Shading
Cut a polygon into multiple parts, such that each is entirely inside or outside the display area
Clip
The process of converting a vector image (shapes) to a raster image (dots)
Rasterization
Why do we rasterize?
Dots are the only things modern displays can
understand
A real value between 0.0 and 1.0, which can be used to fix the length of a line, the speed of an action, or perhaps the size of a picture
Valuator
A coordinate pair (x, y) which enables the -user to point to a position on the display
Locator
Identifies a portion of a picture for further processing
Pick
T/F Some graphics packages allow a picture to be
defined in terms of segments, which are groups of
related graphics primitives
T
What type of device is a joystick?
Locate
What type of device is a trackball?
Valuator
What is an example of a pick device
POS (Point of Sale system)
What can give you strings of characters?
Keyboard
What changes in position?
Mouse
What action is the mouse most often used to perform?
Locate
Provides an area on which the user can slide a stylus
Tablet
What does the frame buffer store?
Array of pixels
What is resolution?
Number of pixels
What is depth?
Number of bits per pixel
Graphics displays are either ____ devices or
____ displays
line-drawing, raster
What are two examples of line drawing devices?
Pen plotter
Vector video device
What is an advantage of vector displays?
Requires very little memory
Conceptually very simple
No aliasing on lines/curves
Refresh rate can be very high
What are the disadvantages of vector displays?
Can only draw line segments
T/F Virtually all displays used today are raster
displays
T
What are the advantages of raster displays?
Refresh rate is not dependent on the amount of
pixels drawn
What are the disadvantages of raster displays?
Need a fairly large amount of memory
Draws the whole screen at once
Need a frame buffer that can hold the information for a whole image
Aliasing
What causes jaggies?
Aliasing
T/F Aliasing is a signal processing problem
T
A ____ uses a strip of photographic film, exposed by the electron beam as it sweeps over it (once) in a raster pattern
Film recorder
