Implement wrapped lighting (direct & IBL diffuse)

1 files changed, 29 insertions, 4 deletions

diff --git a/lighting.cginc b/lighting.cginc
index 500141b..cae24d0 100755
--- a/lighting.cginc
+++ b/lighting.cginc
@@ -147,19 +147,40 @@ float3 yumSH9(float4 n, float3 worldPos, inout LightIndirect light) {
   //
   // L0+L1: dot4 per channel (n.w=1 picks up the L0 term from SHA*.w)
   // L2: four quadratic terms packed into vB via swizzle multiply, plus L22
-  float4 n4 = float4(n.xyz, 1.0);
   float3 L0 = float3(unity_SHAr.w, unity_SHAg.w, unity_SHAb.w);
-  float3 L01 = float3(dot(unity_SHAr, n4), dot(unity_SHAg, n4), dot(unity_SHAb, n4));
-  float4 vB = n4.xyzz * n4.yzzx;
+  float3 L1 = float3(dot(unity_SHAr, n), dot(unity_SHAg, n), dot(unity_SHAb, n));
+  float4 vB = n.xyzz * n.yzzx;
   float3 L2 = float3(dot(unity_SHBr, vB), dot(unity_SHBg, vB), dot(unity_SHBb, vB))
             + unity_SHC * (n.x * n.x - n.y * n.y);
 
+#if defined(_WRAPPED_LIGHTING)
+  // Original coefficients: 1, 2/3, 1/4.
+  // Wrapped coefficients: 1, (2-w)/3, ((1-w)^2)/4.
+
+  // Setting w=0, the l1 band is:
+  //   (2-w)/3 = 2/3
+  //   2-w = 2
+  //   1-w/2 = 1
+  float wrap_amount = _Wrapped_Lighting_Amount;
+  float l1_wrap = 1.0f - wrap_amount * 0.75f;
+  L1 *= l1_wrap;
+
+  // The l2 band is:
+  //   ((1-w)^2)/4 = 1/4
+  //   (1-w)^2 = 1
+  float l2_wrap = (1.0f-wrap_amount);
+  l2_wrap *= l2_wrap;
+  L2 *= l2_wrap;
+#else
+  float l1_wrap = 1.0f;
+#endif  // _WRAPPED_LIGHTING
+
   light.L00 = L0;
   light.L01r = unity_SHAr.xyz;
   light.L01g = unity_SHAg.xyz;
   light.L01b = unity_SHAb.xyz;
 
-  return L01 + L2;
+  return L0 + L1 + L2;
 }
 
 float4 getIndirectDiffuse(v2f i, Pbr pbr, inout LightIndirect light) {
@@ -234,7 +255,11 @@ void GetLighting(v2f i, Pbr pbr, out LightData data) {
 	// Direct lighting
 	data.direct.dir = getDirectLightDirection(i);
 	data.direct.H = normalize(data.common.V + data.direct.dir);
+#if defined(_WRAPPED_LIGHTING)
+  data.direct.NoL = wrapNoL(saturate(dot(pbr.normal, data.direct.dir)), _Wrapped_Lighting_Amount);
+#else
 	data.direct.NoL = saturate(dot(pbr.normal, data.direct.dir));
+#endif
 	data.direct.NoH = saturate(dot(pbr.normal, data.direct.H));
   data.direct.LoH = saturate(dot(data.direct.dir, data.direct.H));
 #if defined(_CLEARCOAT)