Cloth bugfixes; burley tiling scaling fix

1 files changed, 27 insertions, 10 deletions

diff --git a/brdf.cginc b/brdf.cginc
index 65a25c9..75eb295 100755
--- a/brdf.cginc
+++ b/brdf.cginc
@@ -73,7 +73,8 @@ float G_GGXSmith(float roughness, float NoL, float NoV) {
 
 float L_Estevez(float r, float x) {
   // Recover constants according to Table 1.
-  float interpolator = 1 - r * r;
+  float one_minus_r = 1 - r;
+  float interpolator = one_minus_r * one_minus_r;
   float one_minus_i = 1 - interpolator;
   float a = interpolator * 25.3245 + one_minus_i * 21.5473;
   float b = interpolator * 3.32435 + one_minus_i * 3.82987;
@@ -84,20 +85,24 @@ float L_Estevez(float r, float x) {
   return a / (1 + b*pow(x, c)) + d*x + e;
 }
 
-float Lambda_Estevez(float cos_theta, float roughness) {
+float Lambda_Estevez_Raw(float cos_theta, float roughness) {
   // Equation 3
-  float lambda = cos_theta < 0.5
+  return cos_theta < 0.5
     ? exp(L_Estevez(roughness, cos_theta))
     : exp(2 * L_Estevez(roughness, 0.5) - L_Estevez(roughness, 1 - cos_theta));
-  // Equation 4
+}
+
+float Lambda_Estevez_Softened(float cos_theta, float roughness) {
+  // Equation 4 applies only to the light-side term.
+  float lambda = Lambda_Estevez_Raw(cos_theta, roughness);
   return pow(lambda, 1 + 2 * pow(1 - cos_theta, 8));
 }
 
 // Estevez & Kulla "Production Friendly Microfacet Sheen BRDF"
 // Height-correlated Smith: G2 / (4 * NoL * NoV)
 float G_Estevez(float roughness, float NoL, float NoV) {
-  float lambda_l = Lambda_Estevez(NoL, roughness);
-  float lambda_v = Lambda_Estevez(NoV, roughness);
+  float lambda_l = Lambda_Estevez_Softened(NoL, roughness);
+  float lambda_v = Lambda_Estevez_Raw(NoV, roughness);
   return 1.0 / ((1.0 + lambda_l + lambda_v) * 4.0 * NoL * NoV);
 }
 
@@ -124,9 +129,9 @@ float4 brdf(v2f i, Pbr pbr, LightData data, out BrdfData bd) {
   float2 dfg_uv = float2(data.common.NoV, pbr.roughness_perceptual);
   [branch]
   if (textureExists(_DFG_LUT)) {
-    bd.ibl_dfg = _DFG_LUT.SampleLevel(bilinear_clamp_s, dfg_uv, 0).rgb;
+    bd.ibl_dfg = _DFG_LUT.SampleLevel(bilinear_clamp_s, dfg_uv, 0);
   } else {
-    bd.ibl_dfg = float3(1, 1, 1);
+    bd.ibl_dfg = float4(1, 1, 1, 1);
   }
   float3 f0_color = lerp(f0, pbr.albedo.xyz, pbr.metallic);
   float3 energy_comp = 1.0f + f0_color * (1.0f / (bd.ibl_dfg.xxx + bd.ibl_dfg.yyy) - 1.0f);
@@ -136,9 +141,9 @@ float4 brdf(v2f i, Pbr pbr, LightData data, out BrdfData bd) {
   float2 cc_dfg_uv = float2(data.common.NoV_cc, pbr.cc_roughness_perceptual);
   [branch]
   if (textureExists(_DFG_LUT)) {
-    bd.ibl_dfg_cc = _DFG_LUT.SampleLevel(bilinear_clamp_s, cc_dfg_uv, 0).rgb;
+    bd.ibl_dfg_cc = _DFG_LUT.SampleLevel(bilinear_clamp_s, cc_dfg_uv, 0);
   } else {
-    bd.ibl_dfg_cc = float3(1, 1, 1);
+    bd.ibl_dfg_cc = float4(1, 1, 1, 1);
   }
   float3 cc_f0_color = lerp(cc_f0, pbr.albedo.xyz, pbr.metallic);
   float3 cc_energy_comp = 1.0f + cc_f0_color * (1.0f / (bd.ibl_dfg_cc.xxx + bd.ibl_dfg_cc.yyy) - 1.0f);
@@ -167,10 +172,21 @@ float4 brdf(v2f i, Pbr pbr, LightData data, out BrdfData bd) {
     bd.direct_d = D_Estevez(pbr.roughness, data.direct.NoH);
     bd.direct_g = G_Estevez(pbr.roughness, data.direct.NoL, data.common.NoV);
 
+    float4 cloth_dfg_i = bd.ibl_dfg;
+    [branch]
+    if (textureExists(_DFG_LUT)) {
+      float2 cloth_direct_uv = float2(data.direct.NoL, pbr.roughness_perceptual);
+      cloth_dfg_i = _DFG_LUT.SampleLevel(bilinear_clamp_s, cloth_direct_uv, 0);
+    }
+    float3 cloth_alpha_o = cloth_f0 * bd.ibl_dfg.zzz;
+    float3 cloth_alpha_i = cloth_f0 * cloth_dfg_i.www;
+    float cloth_base_scale = luminance(min(1.0f - cloth_alpha_i, 1.0f - cloth_alpha_o));
+
     float3 direct_specular_cloth = (bd.direct_d * bd.direct_g) * bd.direct_f;
     direct_specular_cloth *= data.direct.color * data.direct.NoL;
     direct_specular_cloth *= remainder;
     specular += direct_specular_cloth;
+    remainder *= saturate(cloth_base_scale);
     /*
     float Fd = Fd_Lambertian(data.direct.NoL) / PI;
     float3 direct_diffuse = Fd * pbr.albedo.xyz * data.direct.color;
@@ -232,6 +248,7 @@ float4 brdf(v2f i, Pbr pbr, LightData data, out BrdfData bd) {
     float3 specular_dfg = _Cloth_Sheen.rgb * bd.ibl_dfg.zzz;
     float3 indirect_specular = data.indirect.specular * specular_dfg;
     specular += indirect_specular * remainder * data.common.spec_ao;
+    remainder *= saturate(1.0f - specular_dfg);
 
     float3 indirect_diffuse = pbr.albedo.xyz * data.indirect.diffuse;
     diffuse  += indirect_diffuse * remainder;