Blender Git Loki

Merge branch 'master' into soc-2019-outliner

Add Embree access on GPU

Add shrink BVH4 to BVH2 to use Embree access on GPU

Merge branch 'master' into functions

Comment methods of ArrayRef and StringRef

comment methods of some more data structures

comments for methods of SmallVector

initial code layout for updating the required attributes

allocate attributes arrays in AttributeArraysCore

USD: replaced 'xform_only' with 'weak_export'

An object marked as `weak_export` will only be exported if it has any non-
weak children. When it is exported, it is only written as transform, and
not as full object (so no object data).

USD: Pass 'selected/visible only' flags to the exporter

This isn't handled properly by the exporter yet.

USD: removed ExportSettings class

The `ExportSettings` class was a leftover from the porting of Alembic code,
and is no longer necessary. Without it the code is easier to follow.

No functional changes.

USD: Iterate depsgraph, rather than view layer bases

The depsgraph contains all info we need, and iterating it is more
future-proof than iterating the view layer. This also removes any use of
original data and makes the USD exporter work 100% on evaluated data.

Also contains some other cleanups.

Include BLI_iterator.h in DEG_depsgraph_query.h

The `DEG_xxx_ITER_yyy` iterators need the `ITER_BEGIN` and `ITER_END`
macros defined in BLI_iterator.h.

USD: Avoid use of `default` in `switch`

By avoiding `default` and listing all valid `OB_xxx` cases explicitly the
compiler can warn us about any missing cases in the future.

USD: Introducing experimental USD support

This introduces very limited USD support:

- The USD libraries are expected to be in /opt/usd/, not yet built by
install_deps.sh.
- The code requires cleanup & some restructuring to simplify once the
way we want to iterate over the depsgraph is deemed ok.
- No support for instancing, animation, or other features; all
duplicated objects are made real in the USD file. This is fine for
exporting a linked-in posed character, not so much for thousands of
pebbles etc.
- Debug prints are still in place.

simulate all particle types with description

cleanup copying ArrayRef to pointer

refactor towards supporting multiple particle types

initial particle type intermediate class

fix using wrong length