Glitter: move back to dominant direction for IBL

1 files changed, 22 insertions, 21 deletions

diff --git a/lighting.cginc b/lighting.cginc
index 52c9cac..b6d3f8e 100755
--- a/lighting.cginc
+++ b/lighting.cginc
@@ -42,6 +42,15 @@ float3 getIndirectSpecular(v2f i, float perceptual_roughness, float3 view_dir, f
   return env_refl;
 }
 
+float3 getAverageSHDirection(float3 L1r, float3 L1g, float3 L1b, float3 fallback_dir) {
+  float3 raw_dir = L1r + L1g + L1b;
+  float raw_dir_len = length(raw_dir);
+  if (abs(raw_dir_len) < 1e-3) {
+    return fallback_dir;
+  }
+  return raw_dir / raw_dir_len;
+}
+
 // Geomerics SH evaluation
 // https://community.arm.com/cfs-file/__key/telligent-evolution-components-attachments/01-2066-00-00-00-01-27-70/Simplifying_2D00_Spherical_2D00_Harmonics_2D00_for_2D00_Lighting.pdf
 float shEvaluateDiffuseL1Geomerics(float L0, float3 L1, float3 n) {
@@ -139,22 +148,11 @@ float4 getIndirectDiffuse(v2f i, Pbr pbr, inout LightData light) {
 #endif
 
 #if defined(_SHADOWS) || defined(_SSFD)
-  float3x3 mat = float3x3(
-    light.indirect.L01r,
-    light.indirect.L01g,
-    light.indirect.L01b
-  );
-  // Multiply unit vector by L1 matrix to get vector pointing in direction of
-  // light.
-  float3 raw_dir = mul(mat, float3(1,1,1));
-  float raw_dir_len = length(raw_dir);
-  float3 dom_dir = normalize(mul(mat, float3(1,1,1)));
-  if (abs(raw_dir_len) < 1e-3) {
-    dom_dir = light.direct.dir;
-  } else {
-    dom_dir = raw_dir;
-  }
-  dom_dir = normalize(dom_dir);
+  float3 dom_dir = getAverageSHDirection(
+      light.indirect.L01r,
+      light.indirect.L01g,
+      light.indirect.L01b,
+      light.direct.dir);
   light.indirect.diffuse_dominant_dir = dom_dir;
 #endif
 
@@ -266,11 +264,14 @@ void GetLighting(v2f i, Pbr pbr, out LightData data) {
 	data.indirect.diffuse = getIndirectDiffuse(i, pbr, data);
 	data.indirect.specular = getIndirectSpecular(i, pbr.roughness_perceptual, view_dir, data.indirect.dir, data.indirect.diffuse);
 #if defined(_GLITTER)
+  float3 glitter_indirect_dir = getAverageSHDirection(
+      data.indirect.L01r,
+      data.indirect.L01g,
+      data.indirect.L01b,
+      data.indirect.dir);
   data.glitter = GetGlitterLighting(_Glitter_Amount, _Glitter_Roughness,
       i.uv01.xy, pbr.tbn, pbr.roughness,
-      pbr.normal, data.common.V, data.direct.H, data.indirect.H);
-  data.glitter.indirect_specular = getIndirectSpecular(i, _Glitter_IBL_Roughness,
-      view_dir, data.glitter.indirect_dir, data.indirect.diffuse);
+      pbr.normal, data.common.V, data.direct.H, glitter_indirect_dir);
 #endif
 
   data.common.ao = getAO(i);
@@ -299,9 +300,9 @@ void GetLighting(v2f i, Pbr pbr, out LightData data) {
   data.indirect.specular = HSVtoRGB(tmpHSV);
 
 #if defined(_GLITTER)
-  tmpHSV = RGBtoHSV(data.glitter.indirect_specular);
+  tmpHSV = RGBtoHSV(data.indirect.L00);
   tmpHSV[2] = clamp(tmpHSV[2], 0, _Brightness_Clamp_Max);
-  data.glitter.indirect_specular = HSVtoRGB(tmpHSV);
+  data.indirect.L00 = HSVtoRGB(tmpHSV);
 #endif
 
 #if defined(_CLEARCOAT)