Merge branch 'blender-v2.82-release'

Fix T73070: Disable falloff_shape in the Pose Brush

The Falloff property in the pose brush controls how much deformation
propagates through the ik chain, not by using the distance to the
vertices, so this option does not make sense (it does nothing in the
pose brush code and it disables the 3d paint cursor).

Reviewed By: jbakker

Maniphest Tasks: T73070

Differential Revision: https://developer.blender.org/D6574

Merge branch 'blender-v2.82-release'

Fix T73094: Check all vertices when recalculating the mask flags

When a node was partially/fully hidden, this was causing the mask flags
to update incorrectly because it was not checking all vertices, so they
were assigned the fully_masked state and not updating in the transform
tool and mesh filter.

Reviewed By: jbakker

Maniphest Tasks: T73094

Differential Revision: https://developer.blender.org/D6573

Merge branch 'blender-v2.82-release'

Fix T71712: Free the dynamic mesh preview when rebuilding the PBVH

The PBVH usually is rebuild after a topology change, so it does not make
sense to keep the previous dynamic mesh preview vertex list. This may
cause a crash is the number of vertices of the new mesh (and preview) is
larger previous one. Now the list is deleted with the PBVH and a new one
will be generated using the new mesh when the cursor is updated.

Reviewed By: jbakker

Maniphest Tasks: T71712

Differential Revision: https://developer.blender.org/D6476

Fix T72251: Add rotate brush as constrained by radius for automasking

This brush should be added to the set of brushes where we know which
vertices are going to be affected by the brush when starting the stroke.
This way we can limit the automasking only to those vertices instead of
flood filling the whole mesh from the active vertex.

All brushes that are not in this set will automask by flood filling the
mesh when starting the stroke. To improve this and make it work as most
users expect, we need a fast way to calculate topological distances on
high poly meshes.

Reviewed By: jbakker

Maniphest Tasks: T72251

Differential Revision: https://developer.blender.org/D6376

Fix T72647: Check if the PBVH type makes sense for the sampling mode

Before this it was possible to use the operator with Dyntopo sample mode
with a PBVH type GRIDS or FACES, causing a crash. Now we check first if
the PBVH type is correct before calling the sampling function.

We also check if the PBVH exists, which may also cause a crash.

Reviewed By: jbakker

Maniphest Tasks: T72647

Differential Revision: https://developer.blender.org/D6475

Fix T72830: Check if the mesh has mask data before extractig or slicing

This was causing a crash when the mesh does not have the mask data
initialized. I also added the same check to mask extract as it works the
same way.

Reviewed By: jbakker

Maniphest Tasks: T72830

Differential Revision: https://developer.blender.org/D6513

Sculpt: Pose Brush with Inverse Kinematics

This commits introduces the pose_ik_segments brush property in the Pose Brush. When increasing the IK segments count, the brush generates more segments and weights associations following the topology of the mesh. When moving the brush, these segments are transformed using an IK solver and they are used to deform the mesh.

When pressing Ctrl, the brush controls the segments' roll rotation instead of using the IK solver. The brush falloff controls how much rotation is propagated from the first to the last segment in the chain.

Reviewed By: jbakker

Differential Revision: https://developer.blender.org/D6389