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, 12 insertions, 28 deletions

diff --git a/intern/cycles/kernel/osl/osl_bssrdf.cpp b/intern/cycles/kernel/osl/osl_bssrdf.cpp
index c5ca8616fbd..5d968ed85e0 100644
--- a/intern/cycles/kernel/osl/osl_bssrdf.cpp
+++ b/intern/cycles/kernel/osl/osl_bssrdf.cpp
@@ -32,7 +32,7 @@
 
 #include <OSL/genclosure.h>
 
-#include "kernel/kernel_compat_cpu.h"
+#include "kernel/device/cpu/compat.h"
 #include "kernel/osl/osl_closures.h"
 
 // clang-format off
@@ -50,45 +50,30 @@ CCL_NAMESPACE_BEGIN
 
 using namespace OSL;
 
-static ustring u_cubic("cubic");
-static ustring u_gaussian("gaussian");
-static ustring u_burley("burley");
-static ustring u_principled("principled");
+static ustring u_random_walk_fixed_radius("random_walk_fixed_radius");
 static ustring u_random_walk("random_walk");
-static ustring u_principled_random_walk("principled_random_walk");
 
 class CBSSRDFClosure : public CClosurePrimitive {
  public:
   Bssrdf params;
+  float ior;
   ustring method;
 
   CBSSRDFClosure()
   {
-    params.texture_blur = 0.0f;
-    params.sharpness = 0.0f;
-    params.roughness = 0.0f;
+    params.roughness = FLT_MAX;
+    params.anisotropy = 1.0f;
+    ior = 1.4f;
   }
 
   void setup(ShaderData *sd, int path_flag, float3 weight)
   {
-    if (method == u_cubic) {
-      alloc(sd, path_flag, weight, CLOSURE_BSSRDF_CUBIC_ID);
-    }
-    else if (method == u_gaussian) {
-      alloc(sd, path_flag, weight, CLOSURE_BSSRDF_GAUSSIAN_ID);
-    }
-    else if (method == u_burley) {
-      alloc(sd, path_flag, weight, CLOSURE_BSSRDF_BURLEY_ID);
-    }
-    else if (method == u_principled) {
-      alloc(sd, path_flag, weight, CLOSURE_BSSRDF_PRINCIPLED_ID);
+    if (method == u_random_walk_fixed_radius) {
+      alloc(sd, path_flag, weight, CLOSURE_BSSRDF_RANDOM_WALK_FIXED_RADIUS_ID);
     }
     else if (method == u_random_walk) {
       alloc(sd, path_flag, weight, CLOSURE_BSSRDF_RANDOM_WALK_ID);
     }
-    else if (method == u_principled_random_walk) {
-      alloc(sd, path_flag, weight, CLOSURE_BSSRDF_PRINCIPLED_RANDOM_WALK_ID);
-    }
   }
 
   void alloc(ShaderData *sd, int path_flag, float3 weight, ClosureType type)
@@ -106,11 +91,10 @@ class CBSSRDFClosure : public CClosurePrimitive {
       /* create one closure per color channel */
       bssrdf->radius = params.radius;
       bssrdf->albedo = params.albedo;
-      bssrdf->texture_blur = params.texture_blur;
-      bssrdf->sharpness = params.sharpness;
       bssrdf->N = params.N;
       bssrdf->roughness = params.roughness;
-      sd->flag |= bssrdf_setup(sd, bssrdf, (ClosureType)type);
+      bssrdf->anisotropy = clamp(params.anisotropy, 0.0f, 0.9f);
+      sd->flag |= bssrdf_setup(sd, bssrdf, (ClosureType)type, clamp(ior, 1.01f, 3.8f));
     }
   }
 };
@@ -122,9 +106,9 @@ ClosureParam *closure_bssrdf_params()
       CLOSURE_FLOAT3_PARAM(CBSSRDFClosure, params.N),
       CLOSURE_FLOAT3_PARAM(CBSSRDFClosure, params.radius),
       CLOSURE_FLOAT3_PARAM(CBSSRDFClosure, params.albedo),
-      CLOSURE_FLOAT_KEYPARAM(CBSSRDFClosure, params.texture_blur, "texture_blur"),
-      CLOSURE_FLOAT_KEYPARAM(CBSSRDFClosure, params.sharpness, "sharpness"),
       CLOSURE_FLOAT_KEYPARAM(CBSSRDFClosure, params.roughness, "roughness"),
+      CLOSURE_FLOAT_KEYPARAM(CBSSRDFClosure, ior, "ior"),
+      CLOSURE_FLOAT_KEYPARAM(CBSSRDFClosure, params.anisotropy, "anisotropy"),
       CLOSURE_STRING_KEYPARAM(CBSSRDFClosure, label, "label"),
       CLOSURE_FINISH_PARAM(CBSSRDFClosure)};
   return params;