Shader "Shader/RainGlass"
{Properties{_MainTex("Texture", 2D) = "white" {}_Size("Size",Float) = 1_Distortion("Distortion",range(0,5)) = 4_Blur("Blur",range(0,1)) = 1}SubShader{Tags { "RenderType" = "Opaque" "Queue" = "Transparent"}GrabPass{"_GrabTexture"}Pass{CGPROGRAM#pragma vertex vert#pragma fragment frag#include "UnityCG.cginc"struct appdata{float4 vertex : POSITION;float2 uv : TEXCOORD0;};struct v2f{float2 uv : TEXCOORD0;float4 vertex : SV_POSITION;float4 grabUv : TEXCOORD1;};sampler2D _MainTex;sampler2D _GrabTexture;float4 _MainTex_ST;float _Size;float _Distortion;float _Blur;v2f vert(appdata v){v2f o;o.vertex = UnityObjectToClipPos(v.vertex);o.uv = TRANSFORM_TEX(v.uv, _MainTex);o.grabUv = UNITY_PROJ_COORD(ComputeGrabScreenPos(o.vertex));return o;}float N21(float2 p) {p = frac(p * float2(123.34,345.45));p += dot(p,p + 34.345);return frac(p.x * p.y);}float3 Layer(float2 UV,float t) {float2 aspect = float2(2, 1);float2 uv = UV * _Size * aspect;uv.y += t * 0.25;float2 gv = frac(uv) - 0.5;float2 id = floor(uv);float n = N21(id);t += n * 6.28631;float w = UV.y * 10;float x = (n - 0.5) * 0.8;x += (0.4 - abs(x)) * sin(3 * w) * pow(sin(w),6) * 0.45;float y = -sin(t + sin(t + sin(t) * 0.5)) * 0.45;y -= (gv.x - x) * (gv.x - x);float2 dropPos = (gv - float2(x, y)) / aspect;float drop = smoothstep(0.05,0.03,length(dropPos));float2 dropTrailPos = (gv - float2(x, t * 0.25)) / aspect;dropTrailPos.y = (frac(dropTrailPos.y * 8) / 8) - 0.03;float dropTrail = smoothstep(0.03, 0.02, length(dropTrailPos));float fogTrail = smoothstep(-0.05, 0.05, dropPos.y);fogTrail *= smoothstep(0.5, y, gv.y);dropTrail *= fogTrail;fogTrail *= smoothstep(0.05,0.04,abs(dropPos.x));// col += fogTrail * 0.5;// col += dropTrail;// col += drop;float2 offs = drop * dropPos + dropTrail * dropTrailPos;return float3(offs,fogTrail);}fixed4 frag(v2f i) : SV_Target{float t = fmod(_Time.y,7200);float4 col = 0;//水滴层float3 drops = Layer(i.uv,t);//*是放大UV向量+，—是位移UV向量，瞎j8乘drops += Layer(i.uv * 1.35 + 7.51,t);drops += Layer(i.uv * 0.95 + 1.54,t);drops += Layer(i.uv * 1.57 - 6.54,t);//fogTrail是水滴的拖尾因为我们需要拖尾处清楚所以我们需要取个反减值float fade = 1 - saturate(fwidth(i.uv) * 60);float blur = _Blur * 7 * (1 - drops.z * fade);// col = tex2Dlod(_MainTex,float4(i.uv+drops.xy*_Distortion,0,blur));float2 projUv = i.grabUv.xy / i.grabUv.w;projUv += drops.xy * _Distortion * fade;blur *= 0.01;const float numSamples = 32;float a = N21(i.uv) * 6.2831;for (float i = 0; i < numSamples; i++) {float2 offs = float2(sin(a),cos(a)) * blur;float d = frac(sin((i + 1) * 546) * 5421);d = sqrt(d);offs *= d;col += tex2D(_GrabTexture,projUv + offs);a++;}col /= numSamples;return col;}ENDCG}}
}
