From 5fa1c0ec5b2b59db3858a7dfe9f4001eeeff8cc9 Mon Sep 17 00:00:00 2001
From: yum <yum.food.vr@gmail.com>
Date: Mon, 23 Feb 2026 20:20:31 -0800
Subject: Add ambient occlusion & normal filtering

---
 lighting.cginc | 55 ++++++++++++++++++++++++++++++++++++++++---------------
 1 file changed, 40 insertions(+), 15 deletions(-)

(limited to 'lighting.cginc')

diff --git a/lighting.cginc b/lighting.cginc
index 87a3dfc..28ac25b 100755
--- a/lighting.cginc
+++ b/lighting.cginc
@@ -90,9 +90,9 @@ float4 getDirectLightColorIntensity() {
 	return float4(_LightColor0.xyz, _LightColor0.w);
 }
 
-float3 getIndirectSpecular(v2f i, float roughness, float3 view_dir, float3 reflect_dir) {
+float3 getIndirectSpecular(v2f i, float perceptual_roughness, float3 view_dir, float3 reflect_dir) {
   UnityGIInput data = InitialiseUnityGIInput(i.worldPos, view_dir);
-  float3 env_refl = UnityGI_prefilteredRadiance(data, roughness, reflect_dir);
+  float3 env_refl = UnityGI_prefilteredRadiance(data, perceptual_roughness, reflect_dir);
   return env_refl;
 }
 
@@ -133,23 +133,42 @@ float3 yumSH9(float4 n, float3 worldPos, inout LightIndirect light) {
         dot(light.L01b, n.xyz));
   }
 
-  // Geomerics SH evaluation
-  // Extract L0 and optionally incorporate part of L2
-  float3 L0 = float3(unity_SHAr.w, unity_SHAg.w, unity_SHAb.w);
-  float3 L0L2 = float3(unity_SHBr.z, unity_SHBg.z, unity_SHBb.z) / 3.0;
-  L0 = L0 + L0L2; // useL2 = true
-
-  float3 finalSH;
-  finalSH.r = shEvaluateDiffuseL1Geomerics(L0.r, unity_SHAr.xyz, n.xyz);
-  finalSH.g = shEvaluateDiffuseL1Geomerics(L0.g, unity_SHAg.xyz, n.xyz);
-  finalSH.b = shEvaluateDiffuseL1Geomerics(L0.b, unity_SHAb.xyz, n.xyz);
+  // Unity gives us the first three bands (L0-L2) of SH coefficients as follows:
+  //   unity_SHA*.w:   L0 coefficients
+  //   unity_SHA*.xyz: L1 coefficients
+  //   unity_SHB*:     first four of the L2 coefficients
+  //   unity_SHC:      last L2 coefficient
+
+  // Parse out coefficients into a simpler but less efficient format.
+  float3 L00  = float3(unity_SHAr.w, unity_SHAg.w, unity_SHAb.w);
+  float3 L1_1 = float3(unity_SHAr.x, unity_SHAg.x, unity_SHAb.x);
+  float3 L10  = float3(unity_SHAr.y, unity_SHAg.y, unity_SHAb.y);
+  float3 L11  = float3(unity_SHAr.z, unity_SHAg.z, unity_SHAb.z);
+  float3 L2_2 = float3(unity_SHBr.x, unity_SHBg.x, unity_SHBb.x);
+  float3 L2_1 = float3(unity_SHBr.y, unity_SHBg.y, unity_SHBb.y);
+  float3 L20  = float3(unity_SHBr.z, unity_SHBg.z, unity_SHBb.z);
+  float3 L21  = float3(unity_SHBr.w, unity_SHBg.w, unity_SHBb.w);
+  float3 L22  = unity_SHC;
+
+  // Equation 13 from "An Efficient Representation for Irradiance Environment
+  // Maps" by Ramamoorthi and Hanrahan. Note that the order of some
+  // coefficients is different, and normalization constants have been
+  // premultiplied by Unity.
+  float3 L0 = L00;
+  float3 L1 = L1_1 * n.x + L10 * n.y + L11 * n.z;
+  float3 L2 =
+    L2_2 * n.x * n.y +
+    L2_1 * n.y * n.z +
+    L20  * n.z * n.z +
+    L21 * n.x * n.z +
+    L22 * (n.x * n.x - n.y * n.y);
 
   light.L00 = L0;
   light.L01r = unity_SHAr.xyz;
   light.L01g = unity_SHAg.xyz;
   light.L01b = unity_SHAb.xyz;
 
-  return finalSH;
+  return L0 + L1 + L2;
 }
 
 float4 getIndirectDiffuse(v2f i, Pbr pbr, inout LightIndirect light) {
@@ -157,6 +176,12 @@ float4 getIndirectDiffuse(v2f i, Pbr pbr, inout LightIndirect light) {
 #if defined(FORWARD_BASE_PASS)
   diffuse.xyz += max(0, yumSH9(float4(i.normal, 1.0), i.worldPos, light));
 #endif
+
+#if defined(_AMBIENT_OCCLUSION)
+  diffuse.xyz *= lerp(1, _OcclusionMap.Sample(bilinear_repeat_s, i.uv01.xy), 1);
+  //diffuse.xyz = _OcclusionMap.Sample(bilinear_repeat_s, i.uv01.xy);
+#endif
+
   return diffuse;
 }
 
@@ -208,9 +233,9 @@ void GetLighting(v2f i, Pbr pbr, out LightData data) {
   data.indirect.double_LoV = saturate(2.0f * indirect_LoV * indirect_LoV - 1.0f);
 
 	data.indirect.diffuse = getIndirectDiffuse(i, pbr, data.indirect);
-	data.indirect.specular = getIndirectSpecular(i, pbr.roughness, view_dir, -data.indirect.dir);
+	data.indirect.specular = getIndirectSpecular(i, pbr.roughness_perceptual, view_dir, -data.indirect.dir);
 #if defined(_CLEARCOAT)
-  data.indirect.specular_cc = getIndirectSpecular(i, pbr.cc_roughness, view_dir, dir_cc);
+  data.indirect.specular_cc = getIndirectSpecular(i, saturate(sqrt(pbr.cc_roughness)), view_dir, dir_cc);
 #if defined(_CLEARCOAT_MASK)
   float cc_mask = _Clearcoat_Mask.Sample(bilinear_clamp_s, i.uv01.xy).r;
   data.indirect.specular_cc *= cc_mask;
-- 
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