Merge branch 'blender-v2.82-release'

intern/cycles/kernel/closure/bsdf_principled_sheen.h

@@ -26,13 +26,26 @@ CCL_NAMESPACE_BEGIN
 
 typedef ccl_addr_space struct PrincipledSheenBsdf {
   SHADER_CLOSURE_BASE;
+  float avg_value;
 } PrincipledSheenBsdf;
 
 static_assert(sizeof(ShaderClosure) >= sizeof(PrincipledSheenBsdf),
               "PrincipledSheenBsdf is too large!");
 
-ccl_device float3 calculate_principled_sheen_brdf(
-    const PrincipledSheenBsdf *bsdf, float3 N, float3 V, float3 L, float3 H, float *pdf)
+ccl_device_inline float calculate_avg_principled_sheen_brdf(float3 N, float3 I)
+{
+  /* To compute the average, we set the half-vector to the normal, resulting in
+   * NdotI = NdotL = NdotV = LdotH */
+  float NdotI = dot(N, I);
+  if (NdotI < 0.0f) {
+    return 0.0f;
+  }
+
+  return schlick_fresnel(NdotI) * NdotI;
+}
+
+ccl_device float3
+calculate_principled_sheen_brdf(float3 N, float3 V, float3 L, float3 H, float *pdf)
 {
   float NdotL = dot(N, L);
   float NdotV = dot(N, V);
@@ -49,9 +62,11 @@ ccl_device float3 calculate_principled_sheen_brdf(
   return make_float3(value, value, value);
 }
 
-ccl_device int bsdf_principled_sheen_setup(PrincipledSheenBsdf *bsdf)
+ccl_device int bsdf_principled_sheen_setup(const ShaderData *sd, PrincipledSheenBsdf *bsdf)
 {
   bsdf->type = CLOSURE_BSDF_PRINCIPLED_SHEEN_ID;
+  bsdf->avg_value = calculate_avg_principled_sheen_brdf(bsdf->N, sd->I);
+  bsdf->sample_weight *= bsdf->avg_value;
   return SD_BSDF | SD_BSDF_HAS_EVAL;
 }
 
@@ -69,7 +84,7 @@ ccl_device float3 bsdf_principled_sheen_eval_reflect(const ShaderClosure *sc,
 
   if (dot(N, omega_in) > 0.0f) {
     *pdf = fmaxf(dot(N, omega_in), 0.0f) * M_1_PI_F;
-    return calculate_principled_sheen_brdf(bsdf, N, V, L, H, pdf);
+    return calculate_principled_sheen_brdf(N, V, L, H, pdf);
   }
   else {
     *pdf = 0.0f;
@@ -107,7 +122,7 @@ ccl_device int bsdf_principled_sheen_sample(const ShaderClosure *sc,
   if (dot(Ng, *omega_in) > 0) {
     float3 H = normalize(I + *omega_in);
 
-    *eval = calculate_principled_sheen_brdf(bsdf, N, I, *omega_in, H, pdf);
+    *eval = calculate_principled_sheen_brdf(N, I, *omega_in, H, pdf);
 
 #ifdef __RAY_DIFFERENTIALS__
     // TODO: find a better approximation for the diffuse bounce

intern/cycles/kernel/kernel_passes.h

@@ -80,6 +80,10 @@ ccl_device_inline void kernel_update_denoising_features(KernelGlobals *kg,
         MicrofacetBsdf *bsdf = (MicrofacetBsdf *)sc;
         closure_albedo *= bsdf->extra->fresnel_color;
       }
+      else if (sc->type == CLOSURE_BSDF_PRINCIPLED_SHEEN_ID) {
+        PrincipledSheenBsdf *bsdf = (PrincipledSheenBsdf *)sc;
+        closure_albedo *= bsdf->avg_value;
+      }
 
       albedo += closure_albedo;
       sum_nonspecular_weight += sc->sample_weight;

intern/cycles/kernel/osl/osl_closures.cpp

@@ -197,15 +197,32 @@ CLOSURE_FLOAT3_PARAM(DiffuseClosure, params.N),
     CLOSURE_FLOAT_PARAM(PrincipledDiffuseClosure, params.roughness),
     BSDF_CLOSURE_CLASS_END(PrincipledDiffuse, principled_diffuse)
 
-        BSDF_CLOSURE_CLASS_BEGIN(PrincipledSheen,
-                                 principled_sheen,
-                                 PrincipledSheenBsdf,
-                                 LABEL_DIFFUSE)
-            CLOSURE_FLOAT3_PARAM(PrincipledSheenClosure, params.N),
-    BSDF_CLOSURE_CLASS_END(PrincipledSheen, principled_sheen)
+        class PrincipledSheenClosure : public CBSDFClosure {
+ public:
+  PrincipledSheenBsdf params;
 
-    /* PRINCIPLED HAIR BSDF */
-    class PrincipledHairClosure : public CBSDFClosure {
+  void setup(ShaderData *sd, int path_flag, float3 weight)
+  {
+    if (!skip(sd, path_flag, LABEL_DIFFUSE)) {
+      PrincipledSheenBsdf *bsdf = (PrincipledSheenBsdf *)bsdf_alloc_osl(
+          sd, sizeof(PrincipledSheenBsdf), weight, &params);
+      sd->flag |= (bsdf) ? bsdf_principled_sheen_setup(sd, bsdf) : 0;
+    }
+  }
+};
+
+static ClosureParam *bsdf_principled_sheen_params()
+{
+  static ClosureParam params[] = {CLOSURE_FLOAT3_PARAM(PrincipledSheenClosure, params.N),
+                                  CLOSURE_STRING_KEYPARAM(PrincipledSheenClosure, label, "label"),
+                                  CLOSURE_FINISH_PARAM(PrincipledSheenClosure)};
+  return params;
+}
+
+CCLOSURE_PREPARE_STATIC(closure_bsdf_principled_sheen_prepare, PrincipledSheenClosure)
+
+/* PRINCIPLED HAIR BSDF */
+class PrincipledHairClosure : public CBSDFClosure {
  public:
   PrincipledHairBSDF params;
 
@@ -425,8 +442,11 @@ void OSLShader::register_closures(OSLShadingSystem *ss_)
                    id++,
                    bsdf_principled_diffuse_params(),
                    bsdf_principled_diffuse_prepare);
-  register_closure(
-      ss, "principled_sheen", id++, bsdf_principled_sheen_params(), bsdf_principled_sheen_prepare);
+  register_closure(ss,
+                   "principled_sheen",
+                   id++,
+                   bsdf_principled_sheen_params(),
+                   closure_bsdf_principled_sheen_prepare);
   register_closure(ss,
                    "principled_clearcoat",
                    id++,

intern/cycles/kernel/svm/svm_closure.h

@@ -290,7 +290,7 @@ ccl_device void svm_node_closure_bsdf(KernelGlobals *kg,
           bsdf->N = N;
 
           /* setup bsdf */
-          sd->flag |= bsdf_principled_sheen_setup(bsdf);
+          sd->flag |= bsdf_principled_sheen_setup(sd, bsdf);
         }
       }