Why it is called "screen space"

• Use information only from the screen (post processing method)

Screen Space Ambient Occlusion (SSAO)

Note:

• First introduced in Crytek

Why AO?

• Cheap to implement, but enhances the sense of relative positions

Blinn-Phong Reflection Model (Ambient Light)

• Now consider visibility（每个点可能会被周围的东西遮挡）
• Assuming uniform incident lighting - $L_i$ is constant
• Also assuming diffuse materials (not glossy) - $f_r = \frac{\rho}{\pi}$ is constant

Dive Deep 深入理解

把 Visibility 拆出去

还可以看成是 the average f(x) in the support of g(x)

这种拿出来的近似 split sum 什么时候准确呢？Accuracy