75 lines
1.8 KiB
Text
75 lines
1.8 KiB
Text
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Shader "Unlit/Phase"
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{
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Properties
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{
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_G ("G", Range(-1, 1)) = 0
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_Params ("Params", Vector) = (0,0,0,0)
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[Toggle]
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_UseHG ("UseHG", Float) = 1
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}
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SubShader
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{
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Tags { "RenderType"="Opaque" }
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LOD 100
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Pass
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{
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CGPROGRAM
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#pragma vertex vert
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#pragma fragment frag
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#include "UnityCG.cginc"
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struct appdata
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{
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float4 vertex : POSITION;
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float2 uv : TEXCOORD0;
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};
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struct v2f
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{
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float2 uv : TEXCOORD0;
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float4 vertex : SV_POSITION;
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};
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float _G;
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float4 _Params;
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float _UseHG;
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float phaseRayleight(float cosTheta) {
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return 3/(16*3.1415) * (1+cosTheta * cosTheta);
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}
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float phaseHG(float cosTheta, float g) {
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float a = (3 * (1 - g * g)) / (2 * (2 + g * g));
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float b = (1 + cosTheta * cosTheta) / pow (1 + g*g - 2 * g * cosTheta, 3/2);
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return a * b;
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}
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float phaseHG2(float cosTheta, float g) {
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float g2 = g*g;
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return (1-g2) / (4*3.1415*pow(1+g2-2*g*(cosTheta), 1.5));
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}
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float Schlick(float k, float cosTheta) {
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return (1 - k * k) / (4 * 3.1415 * pow(1.0 - k * cosTheta, 2.0));
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}
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v2f vert (appdata v)
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{
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v2f o;
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o.vertex = UnityObjectToClipPos(v.vertex);
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o.uv = v.uv;
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return o;
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}
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fixed4 frag (v2f i) : SV_Target
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{
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float cosTheta = dot (normalize(i.uv-0.5), float2(1,0));
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return phaseRayleight(cosTheta);
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return phaseHG(cosTheta, _G) * _UseHG + Schlick(_G, cosTheta) * (1-_UseHG);
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}
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ENDCG
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}
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}
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}
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