Computer Graphics Intro.

Computer Graphics

Computer graphics deals with all aspects of creating images with a computer

Example: Where did this image come from?

What hardware/software did we need to produce it?

Application: The object is an artist’s rendition of the sun for an animation to be shown in a domed environment (planetarium)

Software: Maya for modeling and rendering but Maya is built on top of OpenGL

Hardware: PC with graphics card for modeling and rendering

Basic Graphics System

CRT

Can be used either as a line-drawing device (calligraphic) or to display contents of frame buffer (raster mode)

Computer Graphics: 1950-1960

Computer graphics goes back to the earliest days of computing

Cost of refresh for CRT too high

Computer Graphics: 1960-1970

Wireframe graphics

Sketchpad

Display Processors

Storage tube

Sketchpad

Ivan Sutherland’s PhD thesis at MIT

Recognized the potential of man-machine interaction

Sutherland also created many of the now common algorithms for computer graphics

Display Processor

Rather than have the host computer try to refresh display use a special purpose computer called a display processor (DPU)

Graphics stored in display list (display file) on display processor

Host compiles display list and sends to DPU

Computer Graphics: 1970-1980

Raster Graphics

Beginning of graphics standards

Workstations and PCs

Raster Graphics

Image produced as an array (the raster) of picture elements (pixels) in the frame buffer

Raster Graphics-- Allows us to go from lines and wire frame images to filled polygons

The raster is stored as a matrix of pixels representing the entire screen.

The image is scanned out one raster line at a time by the video controller

The frame buffer is memory, part of main memory or video card.  Its depth is the number of bits used for each pixel:

PCs and Workstations

Although we no longer make the distinction between workstations and PCs, historically they evolved from different roots

Computer Graphics: 1980-1990

Realism comes to computer graphics

Special purpose hardware

Industry-based standards

Networked graphics: X Window System

Human-Computer Interface (HCI)

Computer Graphics: 1990-2000

OpenGL API

Completely computer-generated feature-length movies (Toy Story) are successful

New hardware capabilities

Computer Graphics: 2000-

Photorealism

Graphics cards for PCs dominate market

Game boxes and game players determine direction of market

Computer graphics routine in movie industry: Maya, Lightwave

Programmable pipelines

Pipelines

Images

The object