Lecture 13 - Radiosity I

Iref lected k ak n n il iincidentk rs vqvq iincident

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Unformatted text preview: eflectance equation: models light from Recall• thethe reflectance equation: models reflected reflected light surface: surface:from a surface: ! Iref lected k +ak (n · n ·Il) Iincidentk (rs ·(v)qv)q Iincident Iref lected = = k + kd ( l) incident + + k r · Iincident a s d •  Iincident: light intensity ! Iincident : Incident light intensity Iincident : Incident light intensity •  k{a,d,s}: control amounts of: ! k{a,d,s} control amounts of: k{a,d,s} control amounts of: ka: ambient light I ka :– ambient light ! I ka : ambient light –  kd: diffuse light! I k : di↵use reflection I kd : d –  useqreflection reflection! di↵ ks, : specular I ks , q : specular reflection I ks , q : specular reflection Graphics Lecture 13: Slide 6! . 2./ 29 2 / 29 Lighting model for ray tracing " For ray tracing we assumed that there were a small number of point light sources. ! ! However, according to the reflectance equation, every surface is reflecting light, and so should also be considered a light source. ! ! So rather than use a constant for ambient light, shouldn’t we sum the light received from all other surfaces in the scene? ! Graphics Lecture 13: Slide 7! Ambient light Ambient light Ambient light " •  A better approximation to the reflectance equation is to AA better approximation light term a function of theto make the better approximation to the reflectance equation isis incident the make the ambient to the reflectance equation to make ambient lightwell ! a a function of the incident light as well light light term ambient as term function of the incident light as well Iref lected == a Iincident ++ d (nn l)lIincident + ks (r r vvq)q incident Iref lected k ka Iincident k kd ( · · ) Iincident + ks ( · · ) I Iincident Or,  moremore simply, to (for a a(for aviewpoint) • more simply, to write (for given viewpoint) Or,Or, simply, to write write given given viewpoint) ! Iref lected ==...
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This document was uploaded on 03/26/2014.

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