Cycles: merge of cycles-x branch, a major update to the renderer

This includes much improved GPU rendering performance, viewport interactivity,
new shadow catcher, revamped sampling settings, subsurface scattering anisotropy,
new GPU volume sampling, improved PMJ sampling pattern, and more.

Some features have also been removed or changed, breaking backwards compatibility.
Including the removal of the OpenCL backend, for which alternatives are under
development.

Release notes and code docs:
https://wiki.blender.org/wiki/Reference/Release_Notes/3.0/Cycles
https://wiki.blender.org/wiki/Source/Render/Cycles

Credits:
* Sergey Sharybin
* Brecht Van Lommel
* Patrick Mours (OptiX backend)
* Christophe Hery (subsurface scattering anisotropy)
* William Leeson (PMJ sampling pattern)
* Alaska (various fixes and tweaks)
* Thomas Dinges (various fixes)

For the full commit history, see the cycles-x branch. This squashes together
all the changes since intermediate changes would often fail building or tests.

Ref T87839, T87837, T87836
Fixes T90734, T89353, T80267, T80267, T77185, T69800

1 files changed, 8 insertions, 83 deletions

diff --git a/intern/cycles/kernel/closure/bsdf.h b/intern/cycles/kernel/closure/bsdf.h
index 6f2f2ebb202..4eb8bcae997 100644
--- a/intern/cycles/kernel/closure/bsdf.h
+++ b/intern/cycles/kernel/closure/bsdf.h
@@ -14,6 +14,8 @@
  * limitations under the License.
  */
 
+#pragma once
+
 // clang-format off
 #include "kernel/closure/bsdf_ashikhmin_velvet.h"
 #include "kernel/closure/bsdf_diffuse.h"
@@ -109,7 +111,7 @@ ccl_device_inline float shift_cos_in(float cos_in, const float frequency_multipl
   return val;
 }
 
-ccl_device_inline int bsdf_sample(KernelGlobals *kg,
+ccl_device_inline int bsdf_sample(const KernelGlobals *kg,
                                   ShaderData *sd,
                                   const ShaderClosure *sc,
                                   float randu,
@@ -429,21 +431,6 @@ ccl_device_inline int bsdf_sample(KernelGlobals *kg,
       break;
 #  endif /* __PRINCIPLED__ */
 #endif
-#ifdef __VOLUME__
-    case CLOSURE_VOLUME_HENYEY_GREENSTEIN_ID:
-      label = volume_henyey_greenstein_sample(sc,
-                                              sd->I,
-                                              sd->dI.dx,
-                                              sd->dI.dy,
-                                              randu,
-                                              randv,
-                                              eval,
-                                              omega_in,
-                                              &domega_in->dx,
-                                              &domega_in->dy,
-                                              pdf);
-      break;
-#endif
     default:
       label = LABEL_NONE;
       break;
@@ -482,15 +469,16 @@ ccl_device
 ccl_device_inline
 #endif
     float3
-    bsdf_eval(KernelGlobals *kg,
+    bsdf_eval(const KernelGlobals *kg,
               ShaderData *sd,
               const ShaderClosure *sc,
               const float3 omega_in,
+              const bool is_transmission,
               float *pdf)
 {
-  float3 eval;
+  float3 eval = zero_float3();
 
-  if (dot(sd->N, omega_in) >= 0.0f) {
+  if (!is_transmission) {
     switch (sc->type) {
       case CLOSURE_BSDF_DIFFUSE_ID:
       case CLOSURE_BSDF_BSSRDF_ID:
@@ -570,13 +558,7 @@ ccl_device_inline
         break;
 #  endif /* __PRINCIPLED__ */
 #endif
-#ifdef __VOLUME__
-      case CLOSURE_VOLUME_HENYEY_GREENSTEIN_ID:
-        eval = volume_henyey_greenstein_eval_phase(sc, sd->I, omega_in, pdf);
-        break;
-#endif
       default:
-        eval = make_float3(0.0f, 0.0f, 0.0f);
         break;
     }
     if (CLOSURE_IS_BSDF_DIFFUSE(sc->type)) {
@@ -663,13 +645,7 @@ ccl_device_inline
         break;
 #  endif /* __PRINCIPLED__ */
 #endif
-#ifdef __VOLUME__
-      case CLOSURE_VOLUME_HENYEY_GREENSTEIN_ID:
-        eval = volume_henyey_greenstein_eval_phase(sc, sd->I, omega_in, pdf);
-        break;
-#endif
       default:
-        eval = make_float3(0.0f, 0.0f, 0.0f);
         break;
     }
     if (CLOSURE_IS_BSDF_DIFFUSE(sc->type)) {
@@ -682,7 +658,7 @@ ccl_device_inline
   return eval;
 }
 
-ccl_device void bsdf_blur(KernelGlobals *kg, ShaderClosure *sc, float roughness)
+ccl_device void bsdf_blur(const KernelGlobals *kg, ShaderClosure *sc, float roughness)
 {
   /* ToDo: do we want to blur volume closures? */
 #ifdef __SVM__
@@ -715,55 +691,4 @@ ccl_device void bsdf_blur(KernelGlobals *kg, ShaderClosure *sc, float roughness)
 #endif
 }
 
-ccl_device bool bsdf_merge(ShaderClosure *a, ShaderClosure *b)
-{
-#ifdef __SVM__
-  switch (a->type) {
-    case CLOSURE_BSDF_TRANSPARENT_ID:
-      return true;
-    case CLOSURE_BSDF_DIFFUSE_ID:
-    case CLOSURE_BSDF_BSSRDF_ID:
-    case CLOSURE_BSDF_TRANSLUCENT_ID:
-      return bsdf_diffuse_merge(a, b);
-    case CLOSURE_BSDF_OREN_NAYAR_ID:
-      return bsdf_oren_nayar_merge(a, b);
-    case CLOSURE_BSDF_REFLECTION_ID:
-    case CLOSURE_BSDF_REFRACTION_ID:
-    case CLOSURE_BSDF_MICROFACET_GGX_ID:
-    case CLOSURE_BSDF_MICROFACET_GGX_FRESNEL_ID:
-    case CLOSURE_BSDF_MICROFACET_GGX_CLEARCOAT_ID:
-    case CLOSURE_BSDF_MICROFACET_GGX_REFRACTION_ID:
-    case CLOSURE_BSDF_MICROFACET_MULTI_GGX_ID:
-    case CLOSURE_BSDF_MICROFACET_MULTI_GGX_FRESNEL_ID:
-    case CLOSURE_BSDF_MICROFACET_MULTI_GGX_GLASS_ID:
-    case CLOSURE_BSDF_MICROFACET_MULTI_GGX_GLASS_FRESNEL_ID:
-    case CLOSURE_BSDF_MICROFACET_BECKMANN_ID:
-    case CLOSURE_BSDF_MICROFACET_BECKMANN_REFRACTION_ID:
-    case CLOSURE_BSDF_ASHIKHMIN_SHIRLEY_ID:
-      return bsdf_microfacet_merge(a, b);
-    case CLOSURE_BSDF_ASHIKHMIN_VELVET_ID:
-      return bsdf_ashikhmin_velvet_merge(a, b);
-    case CLOSURE_BSDF_DIFFUSE_TOON_ID:
-    case CLOSURE_BSDF_GLOSSY_TOON_ID:
-      return bsdf_toon_merge(a, b);
-    case CLOSURE_BSDF_HAIR_REFLECTION_ID:
-    case CLOSURE_BSDF_HAIR_TRANSMISSION_ID:
-      return bsdf_hair_merge(a, b);
-#  ifdef __PRINCIPLED__
-    case CLOSURE_BSDF_PRINCIPLED_DIFFUSE_ID:
-    case CLOSURE_BSDF_BSSRDF_PRINCIPLED_ID:
-      return bsdf_principled_diffuse_merge(a, b);
-#  endif
-#  ifdef __VOLUME__
-    case CLOSURE_VOLUME_HENYEY_GREENSTEIN_ID:
-      return volume_henyey_greenstein_merge(a, b);
-#  endif
-    default:
-      return false;
-  }
-#else
-  return false;
-#endif
-}
-
 CCL_NAMESPACE_END