UnityShader之毛绒绒效果_游戏中的毛绒绒效果三层透贴

今天要做一个毛球的效果

核心的算法通过多个pass，从里到外一层一层的糊上一层透明diffuse，越靠外面的地方层次越少看起来越稀疏，越模糊

FurHelper.cginc

struct v2f {
	float4 pos : SV_POSITION;
	half2 uv : TEXCOORD0;
	half2 uv1 : TEXCOORD1;
	fixed4 diff : COLOR;
};
 
float _FurLength;
sampler2D _MainTex;
float4 _MainTex_ST;
sampler2D _FurTex;
float4 _FurTex_ST;
float _Blur;
 
v2f vert(appdata_base v) {
	v2f o;
	v.vertex.xyz += v.normal * _FurLength * FURSTEP;
	o.pos = UnityObjectToClipPos(v.vertex);
	o.uv = TRANSFORM_TEX(v.texcoord, _MainTex);
	o.uv1 = TRANSFORM_TEX(v.texcoord, _FurTex);
	float3 worldNormal = normalize(mul(v.normal, (float3x3) unity_WorldToObject));
	o.diff = LambertDiffuse(worldNormal);
	o.diff.a = 1 -