Introduction and Devices

Question 1

Rendering

Answer 1

Conversion of a scene into an image

Question 2

Models

Answer 2

Composition of primitives

Question 3

Graphics pipeline

Answer 3

The processing of compiling models into a scene and converting it into an image

Question 4

Forward projection pipeline

Answer 4

1. Models (MCS)
[T] Modelling Transformations
2. 3D World Scene (WCS)
[T] Viewing Transformations
3. 3D View Scene (VCS)
[F] Projection, Clipping, Normalize
4. 2D/3D Device Scene (NDCS)
[F] Rasterization
5. 2D Image (DCS/SCS)

Question 5

Transformation

Answer 5

Convert representatiosn of models/primitives from one coordinate system to another

Question 6

Clipping/Hidden Surface Removal

Answer 6

Remove primitives and parts of primitives that are not visible on the display

Question 7

Rasterization

Answer 7

Convert a projected screen-space primitive to a set of pixels.

Question 8

Calligraphic Display Devices

Answer 8

Draw polygon and line segments directly. Eg.
1. Plotters
2. Direct Beam Control CRTs
3. Laser Light Projection Systems
They represent an image as a regular grid of samples

Question 9

Raster Display Devices

Answer 9

Each sample is called a pixel (picture element)

Rendering requires an algorithm to determine a sampled representation of geometric primitives.

Question 10

Cathode Ray Tube

Answer 10

CRT. Common display device that uses an electron beam scanned in a regular pattern of horizontal scanlines 
\+ High resolution
\+ Good colour fidelity
\+ High contrast (100:1)
\+ High update rates

Question 11

Where are images stored in a CRT?

Answer 11

Frame Buffer

Question 12

How does a colour CRT work?

Answer 12

It contains three independent electron guns and three different colours of phosphor. Shadow masks allow each gun to irradiate only one colour of phosphor.

Question 13

Liquid Crystal Displays

Answer 13

LCD. Flat panel displays. Works by allowing random access to cells containing liquid crystal molecules that align when charged. Unaligned molecules twist the light and polarizing filters only light only through unaligned molecules.
Subpixel colour filter masks are used for RGB colour.