Blender Git Loki

Ported key owner type code from gooseberry, to better sync both branches.

The shapekey code has been modified in both branches, adding particle
shapekeys in gooseberry and cache library shapekeys in alembic. The
two approaches are slightly different, but based on the same idea of
extending the 'from' owner info in Key, so that keys can be used without
a 'from' ID and/or with an index for identification.

Improved relaxation code for strand lengths in hair edit mode.

Fix for incorrect vertex loops when calculating strands.

This was using vprev from previous strands, leading to spurious changes
on untouched strands when combing.

Merge branch 'master' into alembic

Use the extended archive writer variant to set the correct start frame
for slices.

Also the time sampling for slice output properties must be passed down
from the output archive, since the input properties use the original
start frame and cycle times.

Use fps and start frame settings for cache archives internally, rather
than relying on values from Scene.

This gives more flexibility when creating archives. A default variant
for opening archives using the scene settings is still available.

New operator for 'splicing' Alembic data, i.e. writing part of the frame
range to a new archive.

This feature is useful when cache size becomes to big and unwieldy.
For sending shots to a render farm a large cache can now be split into
smaller parts, which are spliced off and can be sent individually.

Optional arguments for the cache baking operator to chose a frame range.

If these properties are left undefined the operator will use the scene
frame range as before.

Very basic printing of cache bake info to have some feedback in
background mode.

Removed redundant particle matrix calculation when writing hair caches.

This could give a significant improvement in cache baking speed. The
particle matrix is particularly costly to calculate for highly
subdivided meshes.

Merge branch 'master' into alembic

Conflicts:
build_files/scons/tools/Blender.py
source/blender/blenkernel/intern/mesh.c

Fix for Drag force fields: was using inverted velocity.

Fix for previous commit: the "goal deflect" feature wasn't actually
filtering effectors by type.

Optional feature "Goal Deflect" to disable goal forces when hitting a
deflector object.

Revert "Disabled the goal spring that is supposed to stabilize roots."

This reverts commit 1b32ac9779c709918c3bf9d46e9e4bb1892dd8bc.

The goal spring is not working as intended, but is better than having
no bending force at the roots at all. Needs a better solution (virtual
root vertex).

Fix for incorrect sub-stepping in the strands hair sim solver.

The code was copied from the old cloth solver, which used a while loop.
Ended up using double step increments, which screwed up some
calculations ...

Fix for initialization of effector velocities.

Disabled the goal spring that is supposed to stabilize roots.

There are larger bugs still roaming free which need to be solved first.
Goal springs also are inherently unstable because the solver can not
properly estimate their Jacobian.

Fix for crash when using cache file paths without slashes in them.

Fix for potential NULL pointer access when looking up strands data from
caches.

The 'find' function was returning a bool value, but this does not
guarantee non-null pointers. Removed the return value to avoid
confusion, now callers should simply check the returned pointers.