Shading Model

area source

light source

illumination

shadows

material

atmospheric effects

types of light source

luminous intensity

distribution

spectral distribution

direction illumnation

indirect illumnation ( ambient light or radiosity )

umbra

penumbra

reflection (diffuse/specular reflection )

refraction and transparency

light scattering

light absorption

linear source

point source

parallel source (direct sunlight )

skylight

volume source