Further Simple Illumination Effects
- Light attenuation:
- light intensity falls off with the square of the distance from the source - so we add an extra term for this
with d the light source to surface distance - more complicated formulae are possible (see Foley) and work better
Colored lights and surfaces:
- just have three separate equations for RGB (or CIE, YIQ, etc.)
Atmospheric attenuation:
- use viewer-to-surface distance to give extra effects
- the distance is used to blend the object’s radiant color with a “far” color (e.g., a nice hazy gray)