Also, Vectrex was a
vector-based home game console from 1982-4. A commercial failure, but still has a fan base.
Get them on eBay for $400-$3000.
Examples of old arcade games: Atari Asteroids, Battlezone, Tempest, Star Wars.
Note the multi-colour displays. I suspect they are raster simulations of vectors.
Raster displays
based on television technology
screen is divided into pixels at some resolution (fineness)
refresh buffer contains digital information that is converted
directly into screen pixels by hardware
raster: set of raster lines or rows of pixels
when you change some bits in the raster, the screen is changed
television technology has improved resolution
the bigger and finer the picture, the larger the memory
req'd for the refresh buffer. But memory is now cheap!
Raster refresh
Comparing Raster and Vector
advantages of vector:
higher resolution, especially for diagonal lines
geometry objects (lines) whereas raster only handles pixels
eg. 1000 line plot: vector disply computes 2000 endpoints
raster display computes all pixels on each line
advantages of raster:
cheaper
colours, textures, realism
unlimited complexity of picture: whatever you put in refresh buffer,
whereas vector complexity limited by refresh rate
Flat-panel displays
2 main types: emissive (plasma) and non-emissive (LCD)
initially, low-level device-dependent packages were the norm
movement towards high-level device-independent packages, in order to
promote application program portability
requires standardization:
3D Core Graphics System ("Core") dev'd in late 70's as unofficial
std
GKS (Graphical Kernel System, 1985): official 2D standard built from
Core
GKS-3D (1988): 3d objects
PHIGS (Programmer's Hierarchical Interactive Graphics System, 1988)
3d nested objects
PHIGS+ (1988): rendering enhancements
GL: SGI, from early 90's
OpenGL: new standard, open version of GL
Renderman: Pixar rendering language
Direct-3D: Microsoft Windows 3D standard
Java 3D: Java 3D library (www.java3d.org)
CG, OpenGL 3.0 GLSL: vertex and pixel shading
OpenGL ES: for embedded systems (phones, tablets, game consoles)
Preview
Application model: mathematical model of objects to be displayed
eg. data structure containing the coordinates of a polygon
Application program: program that defines application model,
defines what user does with it, process user input, etc
Graphics system: software and hardware component that takes
application model, and using directions from application program, transforms
them into a visual object on screen (printer, plotter, ...)
Preview
the types of transformations the graphics system performs on model
is primary focus of this course
the models are mathematical: lots of trig, matrix multiplication, calculus
(when you get into splines)
graphics is a good example of applied mathematics: abstract mathematical
representations of physical objects are mathematically transformed into
pseudo-realistic representations on the screen
graphics naturally falls into conceptual categories of 2D (drawing
on the plane) and 3D (drawing in 3D space), and the transition area between
them
usually math is "intensive" when techniques or algorithms
are being derived
once the formula and algorithm is derived, they're implemented into
graphics libraries
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