Switch to Mochie's BRDF

Better than Unity BRDF and supports things like parameterizable
half-lambertian lighting.

1 files changed, 83 insertions, 0 deletions

diff --git a/MochieStandardSSS.cginc b/MochieStandardSSS.cginc
new file mode 100644
index 0000000..1d5ffbf
--- /dev/null
+++ b/MochieStandardSSS.cginc
@@ -0,0 +1,83 @@
+#ifndef MOCHIE_STANDARD_SSS_INCLUDED
+#define MOCHIE_STANDARD_SSS_INCLUDED
+
+/*
+ * MIT License
+ *
+ * Copyright (c) 2020 MochiesCode
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to
+ * deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all
+ * copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+ * FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE
+ * SOFTWARE.
+ */
+
+float3 GetSubsurfaceLight(
+	float3 lightColor, float3 lightDirection, float3 normalDirection, float3 viewDirection, 
+    float attenuation, float3 thickness, float3 indirectLight, float3 subsurfaceColor
+){
+    float3 vLTLight = lightDirection + normalDirection * _ScatterDist; // Distortion
+    float3 fLTDot = pow(saturate(dot(viewDirection, -vLTLight)), _ScatterPow) * _ScatterIntensity * 1.0/UNITY_PI; 
+    
+    return lerp(1, attenuation, float(any(_WorldSpaceLightPos0.xyz))) 
+                * (fLTDot + _ScatterAmbient) * thickness
+                * (lightColor + indirectLight) * subsurfaceColor;
+                
+}
+
+float3 GeneralWrapSH(float fA){
+    // Normalization factor for our model.
+    float norm = 0.5 * (2 + fA) / (1 + fA);
+    float4 t = float4(2 * (fA + 1), fA + 2, fA + 3, fA + 4);
+    return norm * float3(t.x / t.y, 2 * t.x / (t.y * t.z),
+        t.x * (fA * fA - t.x + 5) / (t.y * t.z * t.w));
+}
+
+float3 ShadeSH9_wrappedCorrect(float3 normal, float3 conv){
+    const float3 cosconv_inv = float3(1, 1.5, 4); // Inverse of the pre-applied cosine convolution
+    float3 x0, x1, x2;
+    conv *= cosconv_inv; // Undo pre-applied cosine convolution
+    //conv *= _Bands.xyz; // debugging
+
+    // Constant (L0)
+    x0 = float3(unity_SHAr.w, unity_SHAg.w, unity_SHAb.w);
+    // Remove the constant part from L2 and add it back with correct convolution
+    float3 otherband = float3(unity_SHBr.z, unity_SHBg.z, unity_SHBb.z) / 3.0;
+    x0 = (x0 + otherband) * conv.x - otherband * conv.z;
+
+    // Linear (L1) polynomial terms
+    x1.r = (dot(unity_SHAr.xyz, normal));
+    x1.g = (dot(unity_SHAg.xyz, normal));
+    x1.b = (dot(unity_SHAb.xyz, normal));
+
+    // 4 of the quadratic (L2) polynomials
+    float4 vB = normal.xyzz * normal.yzzx;
+    x2.r = dot(unity_SHBr, vB);
+    x2.g = dot(unity_SHBg, vB);
+    x2.b = dot(unity_SHBb, vB);
+
+    // Final (5th) quadratic (L2) polynomial
+    float vC = normal.x * normal.x - normal.y * normal.y;
+    x2 += unity_SHC.rgb * vC;
+
+    return x0 + x1 * conv.y + x2 * conv.z;
+}
+
+#endif // UNITY_STANDARD_SSS_INCLUDED