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, 9 insertions, 30 deletions

diff --git a/source/blender/makesrna/intern/rna_nodetree.c b/source/blender/makesrna/intern/rna_nodetree.c
index d0bf60d5d02..ec53f35df4c 100644
--- a/source/blender/makesrna/intern/rna_nodetree.c
+++ b/source/blender/makesrna/intern/rna_nodetree.c
@@ -4665,16 +4665,18 @@ static const EnumPropertyItem node_principled_distribution_items[] = {
 };
 
 static const EnumPropertyItem node_subsurface_method_items[] = {
-    {SHD_SUBSURFACE_BURLEY,
-     "BURLEY",
+    {SHD_SUBSURFACE_RANDOM_WALK_FIXED_RADIUS,
+     "RANDOM_WALK_FIXED_RADIUS",
      0,
-     "Christensen-Burley",
-     "Approximation to physically based volume scattering"},
+     "Random Walk (Fixed Radius)",
+     "Volumetric approximation to physically based volume scattering, using the scattering radius "
+     "as specified"},
     {SHD_SUBSURFACE_RANDOM_WALK,
      "RANDOM_WALK",
      0,
      "Random Walk",
-     "Volumetric approximation to physically based volume scattering"},
+     "Volumetric approximation to physically based volume scattering, with scattering radius "
+     "automatically adjusted to match color textures"},
     {0, NULL, 0, NULL, NULL}};
 
 /* -- Common nodes ---------------------------------------------------------- */
@@ -6144,35 +6146,12 @@ static void def_sh_ambient_occlusion(StructRNA *srna)
 
 static void def_sh_subsurface(StructRNA *srna)
 {
-  static const EnumPropertyItem prop_subsurface_falloff_items[] = {
-      {SHD_SUBSURFACE_CUBIC, "CUBIC", 0, "Cubic", "Simple cubic falloff function"},
-      {SHD_SUBSURFACE_GAUSSIAN,
-       "GAUSSIAN",
-       0,
-       "Gaussian",
-       "Normal distribution, multiple can be combined to fit more complex profiles"},
-      {SHD_SUBSURFACE_BURLEY,
-       "BURLEY",
-       0,
-       "Christensen-Burley",
-       "Approximation to physically based volume scattering"},
-      {SHD_SUBSURFACE_RANDOM_WALK,
-       "RANDOM_WALK",
-       0,
-       "Random Walk",
-       "Volumetric approximation to physically based volume scattering"},
-      {0, NULL, 0, NULL, NULL},
-  };
-
   PropertyRNA *prop;
 
   prop = RNA_def_property(srna, "falloff", PROP_ENUM, PROP_NONE);
   RNA_def_property_enum_sdna(prop, NULL, "custom1");
-  RNA_def_property_enum_items(prop, prop_subsurface_falloff_items);
-  RNA_def_property_ui_text(prop,
-                           "Falloff",
-                           "Function to determine how much light nearby points contribute based "
-                           "on their distance to the shading point");
+  RNA_def_property_enum_items(prop, node_subsurface_method_items);
+  RNA_def_property_ui_text(prop, "Method", "Method for rendering subsurface scattering");
   RNA_def_property_update(prop, NC_NODE | NA_EDITED, "rna_ShaderNode_socket_update");
 }