Module 1: Lighting

The key points from this module are:
The process of computing luminous intensity (i.e., outgoing light) at a point is called Lighting.
The transport of light energy from the source to the point is called Illumination.
Shading refers to the process of assigning light to a pixel.
The 3 types of light sources in Graphics are:

Point Light Source
Directional Source
Ambient Light

In the Simple Lighting Model, the light intensity reaching the viewer from a surface point can be modeled as the sum of three intensities.
Lambert’s Cosine Law states that energy reflected by a small portion of a surface from a light source in a given direction is proportional to the cosine of the angle between the direction and the surface normal.
Shading Models are carried out at the pixel level after the scene is mapped to the screen or after the rendering is done.
The three types of Shading Models are:

Flat Shading
Phong Shading
Gouraud Shading

The Mapping Scheme distributes the computed values among the system-supported values such that the distribution corresponds to the way our eyes perceive intensity difference.