STARTING OFF:

Make sure you have npm installed. Run:

npm install http-server -g

Run:

http-server

View at: http://localhost:8080/0074-lighting-part-3-picking

• NOTE: moved vendor and images out of folder.
  • Running from main directory instead inside this directory.

CONCEPTS:

• Lighting
• Surface color by diffuse reflection = light color * base color of surface * cos A
  • Diffuse reflection = reflection differs by light position
  • Angle(A) = between the light and surface
• Surface color by ambient reflection = light color * base color of surface
  • Ambient reflection = same reflection at any position
• Surface color by diffuse and ambient reflection = surface color by diffuse + surface color by ambient

Examples:

• if light source is white (1.0,1.0,1.0) such as the sun
• base color is green (0.0,1.0,0.0)
• angle is 0.0 (perpendicular), then cos A = 1.0

R = 1 * 0 * 1 = 0.0 G = 1 * 1 * 1 = 1.0 B = 1 * 0 * 1 = 0.0

• if light source is white (1.0,1.0,1.0) such as the sun
• base color is green (0.0,1.0,0.0)
• angle is 60 degrees, then cos A = 0.5

R = 1 * 0 * 0.5 = 0.0 G = 1 * 1 * 0.5 = 0.5 B = 1 * 0 * 0.5 = 0.0

Calculating Cos A

Cos A = light direction (dot) orientation of a surface

• Dot product
• Normalization (vector lengths must be 1.0)

Normals

Surfaces have two normals- front and back.

RESOURCES:

• https://github.com/davidwparker/programmingtil-webgl/tree/master/0074-lighting-part-3-picking