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, 4 insertions, 2 deletions

diff --git a/intern/cycles/kernel/geom/geom_volume.h b/intern/cycles/kernel/geom/geom_volume.h
index 809b76245ba..2bcd7e56b5f 100644
--- a/intern/cycles/kernel/geom/geom_volume.h
+++ b/intern/cycles/kernel/geom/geom_volume.h
@@ -23,13 +23,15 @@
  * 3D voxel textures can be assigned as attributes per mesh, which means the
  * same shader can be used for volume objects with different densities, etc. */
 
+#pragma once
+
 CCL_NAMESPACE_BEGIN
 
 #ifdef __VOLUME__
 
 /* Return position normalized to 0..1 in mesh bounds */
 
-ccl_device_inline float3 volume_normalized_position(KernelGlobals *kg,
+ccl_device_inline float3 volume_normalized_position(const KernelGlobals *kg,
                                                     const ShaderData *sd,
                                                     float3 P)
 {
@@ -68,7 +70,7 @@ ccl_device float3 volume_attribute_value_to_float3(const float4 value)
   }
 }
 
-ccl_device float4 volume_attribute_float4(KernelGlobals *kg,
+ccl_device float4 volume_attribute_float4(const KernelGlobals *kg,
                                           const ShaderData *sd,
                                           const AttributeDescriptor desc)
 {