Blender Git Loki

Merge branch 'soc-2021-porting-modifiers-to-nodes-extrude' into soc-2021-porting-modifiers-to-nodes

# Conflicts:
# release/scripts/startup/nodeitems_builtins.py
# source/blender/blenkernel/BKE_node.h
# source/blender/bmesh/intern/bmesh_mesh.c
# source/blender/bmesh/intern/bmesh_mesh.h

Merge branch 'soc-2021-porting-modifiers-to-nodes-decimate' into soc-2021-porting-modifiers-to-nodes

Reuse MeshExtract run data facility.

Use C++ for the main subdivision file.

Reuse the MeshExtract APIs to build buffers.

Fix T88552: Cycles changing Render Passes in viewport does not work

Backporting this fixes T90599.

Merge branch 'master' into soc-2021-vse-strip-thumbnails

Fix : Last thumb with error in crop values

Cycles X: add anisotropic random walk SSS

This adds new Subsurface Anisotropy and IOR to the Principled BSDF and
Subsurface Scattering nodes. Real world skin has an anisotropy of around
0.8 and this makes it possible to simulate that more accurately.

Based on the paper: "Path Traced Subsurface Scattering using Anisotropic
Phase Functions and Non-Exponential Free Flights"
https://graphics.pixar.com/library/PathTracedSubsurface/

This comes with a new albedo inversion that gives different results than
the old one. For that reason there is now a Random Walk and Random Walk
(Fixed Radius) option. The latter is provided for backwards compatibility,
and uses the radius exactly as specified. The new one adjust the radius
based on albedo and IOR.

Differential Revision: https://developer.blender.org/D11965

Cleanup: remove a bit more unused diffusion BSSRDF code

refactor variable store

Fix pass memory leak in Cycles X

Differential Revision: https://developer.blender.org/D12248

Cycles X: Write all passes on cancel

Makes it possible to cancel rendering and have current state of all
passes written to the render result, matching old behavior.

Differential Revision: https://developer.blender.org/D12246

add single test

Version bump: 2.93.3-release

cleanup instruction scheduling

Fix wrong viewport render when enabling adaptive sampling in Cycles X

Steps to reproduce:
- Start viewport render
- Enable adaptive sampling

Caused by d5019b3838c: integrator's device update did not properly
detect change in sampler and hence did not rebuild the sampler LUT.

fixes after merge

Merge branch 'master' into greasepencil-object

Merge branch 'master' into mf-procedure