Roughly integrate glitter into brdf

1 files changed, 16 insertions, 3 deletions

diff --git a/brdf.cginc b/brdf.cginc
index de222e7..8bd0061 100755
--- a/brdf.cginc
+++ b/brdf.cginc
@@ -101,7 +101,7 @@ float G_Estevez(float roughness, float NoL, float NoV) {
   return 1.0 / ((1.0 + lambda_l + lambda_v) * 4.0 * NoL * NoV);
 }
 
-float4 brdf(Pbr pbr, LightData data, out BrdfData bd) {
+float4 brdf(v2f i, Pbr pbr, LightData data, out BrdfData bd) {
   bd = (BrdfData)0;
   float3 specular = 0;
   float3 diffuse = 0;
@@ -178,13 +178,26 @@ float4 brdf(Pbr pbr, LightData data, out BrdfData bd) {
     direct_diffuse = max(0, direct_diffuse);
     diffuse += direct_diffuse;
 #else
+    float3 direct_energy = energy_comp;
+    bd.direct_g = G_GGXSmith(pbr.roughness, data.direct.NoL, data.common.NoV);
+#if defined(_GLITTER)
+    float2 glitter_uv = frac(i.uv01.xy);
+    float2x2 glitter_uv_J = uv_ellipsoid(mat2_from_cols(ddx(glitter_uv), ddy(glitter_uv)));
+    float3 H_tangent = mul(data.direct.H, transpose(pbr.tbn));
+    const float glitter_filter_size = 0.7f;
+    float glitter_N = 8.0e5f * pow(10.0f, _Glitter_Amount * 6.0f - 2.0f);
+    bd.direct_f = F_Schlick(data.direct.LoH, 0.96f, 1.0f);
+    bd.direct_d = D_Kemppinen(H_tangent, pbr.roughness, _Glitter_Roughness,
+        glitter_uv, glitter_uv_J, glitter_N, glitter_filter_size);
+    direct_energy = 1.0f;
+#else
     bd.direct_f = F_Schlick(data.direct.LoH, f0_color, f90);
     bd.direct_d = D_GGX(pbr.roughness, data.direct.NoH);
-    bd.direct_g = G_GGXSmith(pbr.roughness, data.direct.NoL, data.common.NoV);
+#endif
 
     float3 direct_specular = (bd.direct_d * bd.direct_g) * bd.direct_f;
     direct_specular *= data.direct.color * data.direct.NoL;
-    direct_specular *= energy_comp;
+    direct_specular *= direct_energy;
     direct_specular *= remainder;
     specular += direct_specular;