The Rendering Equation [Kajiya 86]





I(X,X'): intensity passing from X' to X
e(X,X'): emitted light intensity from X' to X
p(X,X',X"): intensity of light reflected from X" to X from the surface at X'
g(X,X') = 0 if X' is invisible from X

	             if visible

I(X,X'):	intensity passing from X' to X
e(X,X'):	emitted light intensity from X' to X
p(X,X',X"):	intensity of light reflected from X" to X from the surface at X'
g(X,X') =	0 if X' is invisible from X if visible