Screen Space Reflection(...seemed to be very useful...)

Light ​

Compute reflection ray ​

Trace along ray direction ​

[Raymarch]

depth [mipmap]([bvh] [kd-tree])

Hierarchical tracing

mip = 0

Edge fading

Shading ​

想到rsm...

点 $p$ 收到的入射光 $L_i$，其实是从其他地方（点 $q$）反射过来的出射光 $L_o$。