Multi-pass Fur

This is a multi-pass fur render technique shared by Tencent Games.
I tried to reproduce it in unity shaderlab to adopt it in my own game demo.
It can produce intriguing effects like animal fur, cloth and velvet, etc.

The basic idea of its shaderlab code is to:
(1) "Squeeze out" the vertex in every pass(for example, 20 passes in my shader)
(2) Use a noise map and decrease alpha value in every pass, so that the fur's tip will be thinner.
(3) Add SH light, diffuse light, specular light and fresnel rim light to simulate the fur quality.
(4) Add occlusion and shadow to the fur
(5) Add direction, or even wind movement to the fur

There is one more thing that, this shader can merely be adopted in unity built-in render pipeline, and I'm currently working on the URP version with Unity URP render feature.