Blender Git Loki

Cycles: Couple of fixes for hair BVH

- Use proper boudbox offset for primitive packing
- Use proper-ish boundbox for object nodes.

Merge branch 'master' into cycles_hair_bvh

Refactor BKE_blender into:

- BKE_blender_version.h (only version defines & versionstr)
- BKE_blender_copybuffer.h (currently only used for view3d copy/paste)
- BKE_blender_undo.h (global undo functions)
- BKE_blendfile.h (high level blend file read/write API)

Reviewers: sergey, mont29

Differential Revision: https://developer.blender.org/D1947

removed some deprecated functions

simplified grid pointer access functions

Cycles: Proof-of-concept unaligned BVH traversal code

This a commit which breaks regular non-development work broken,
this is due to accumulated TODOs in the code, solving which is
not fully trivial and trying to stub them will lead to some
nasty code. That being said, only final renders are working
stable, perhaps only for hair tho (mixed hair and triangles
could behave flackey).

In any way, the code is mainly here to see how much traversal
steps we can save using oriented bounding boxes in hair BVH,
it is not optimized or vectorized. In fact, it does evaluation
of particular things multiple times. This means only traversal
steps pass could be used to quantify possible improvements.

But that being said some quick tests seems promising. Here is
a camera rays traversal heatmap for suzanne with 8000 hair:

Master: http://www.pasteall.org/pic/show.php?id=102281
Branch: http://www.pasteall.org/pic/show.php?id=102282

Btw, only regular BVH was modified to support OBB.

Now we need to work on vectorization and QBVH support to see
if we can beat performance of AABB by a measurable matter.

Merge branch 'master' into cycles_hair_bvh

Cycles: Initial implementation of unaligned BVH builder

The idea is to use unaligned boundbox nodes for hair BVH, which should
in theory improve performance of ray-to-hair intersection.

Only tree building is done currently, still needed to work on packing
and traversal code.

The idea oh builder is the following:

- We calculate SAH of regular split
- Then we calculate alignment orientation for the BVH range, using
first curve from the range to define orientation.
- Then we calculate SAH using alignment from the previous step.
- If SAH calculated for a found orientation is better than regular
orientation we create unaligned node.
- All leaf nodes are unaligned.

There is some code duplication which we can avoid, and some parts are
not really optimized yet.

Merge branch 'master' into cycles_hair_bvh

Moved function declarations for modifier stack eval into BKE_modifier_calc.h.

Avoid shadowing 'mask' function parameter by a local variable.

Moved code for modifier evaluation out of DerivedMesh.c.

These files contained a confusing mix of DM code (for manipulating DMs
and various utility functions relating to these types), and the code
for evaluating object modifier stacks. These are two very distinct
areas and putting them in a single huge file doesn't promote code
clarity at all.

This commit only moves code, but does not alter any of it. This is
important for log continuity, so history of specific functions can be
clearly traced back!

Actually hook async job of asset updating!

Add 'ensure_uuids' callback to API, fix some flags in RNA code.

Merge branch 'master' into temp_depsgraph_split_ubereval

Make opening .blend file use new async 'check asset updates' operator.

Nothing much exciting really, just not blocking anymore.

Fix unused function warning.

Merge branch 'master' into asset-engine

Conflicts:
source/blender/windowmanager/intern/wm_operators.c

Merge branch 'master' into id-remap

Conflicts:
source/blender/windowmanager/intern/wm_operators.c

Fix meamleak from unfreed edit data when exiting in hair edit mode.