Blender Git Loki

Added writers for DupliCache data to allow truely successive cache
modification.

The bake operator will now generate output based on the 'source_mode'
setting:
* When the source is SCENE it uses the basic object data as stored in
the Object ID datablocks (DerivedMesh, particle hair strands etc.)
* When the source is CACHE it fills a temporary DupliCache with data
from the cache archive (like it would for the display dupli_cache,
but also supporting render data). This dupli cache is carried over
between frames during baking, which allows modifiers to act as
simulations and sequentially advance motion states.

Merge branch 'master' into gooseberry

Merge branch 'master' into cycles_point_density

Merge branch 'alembic' into gooseberry

Merge branch 'cycles_point_density' into gooseberry

Fix compilation error of blender player

Merge branch 'master' into gooseberry

GHash iterator wrapper for DupliCache, so cache modifiers can access
all components in the cache.

Removed unused "object cache" iterator code.

Merge branch 'cycles_point_density' into gooseberry

Added transient DupliCache data baking modifiers/simulations and
writing into the output cache archive.

Merge branch 'alembic' into gooseberry

Conflicts:
source/blender/editors/space_view3d/view3d_intern.h
source/blender/makesrna/intern/rna_modifier.c

Removed the Cache modifier because it is unused now and causes some
merge conflicts with master.

Merge branch 'master' into alembic

Conflicts:
source/blender/blenloader/intern/readfile.c
source/blender/editors/space_view3d/view3d_intern.h
source/blender/makesdna/DNA_modifier_types.h
source/blender/makesrna/intern/rna_modifier.c
source/blender/modifiers/MOD_modifiertypes.h
source/blender/modifiers/intern/MOD_util.c

Cycles: Point density texture experiment

This commit implements point density texture for Cycles shading nodes.

It's done via creating voxel texture at shader compilation time, Not
totally memory efficient, but avoids adding sampling code to kernel
(which keeps render time as low as possible), In the future this will
be compensated by using OpenVDB for more efficient storage of sparse
volume data.

Sampling of the voxel texture is happening at blender side and the
same code is used as for Blender Internal's renderer.

This texture is controlled by only object, particle system and radius.
Linear falloff is used and there's no turbulence. This is because
falloff is expected to happen using Curve Mapping node. Turbulence
will be done as a distortion on the input coordinate. It's already
possible to fake it using nose textures and in the future we can add
more proper turbulence distortion node, which then could also be used
for 2D texture mapping.

OSL is not currently supported. There's no actual stoppers for support
it, but so far it's not really a priority at this point.

Reviewers: campbellbarton, juicyfruit, brecht

Subscribers: campbellbarton, dingto, eyecandy

Differential Revision: https://developer.blender.org/D1208

Removed the redundant cache exporter class from the pointcache lib.

Writing in C++ is a little bit more convenient, but this functionality
does not require the additional level of complexity.

Support for shading "normals" in strand rendering.

Note that the fixed-function OpenGL pipeline does not support true
strand normals. The shading model used copies the method implemented for
particles, using the edge directions as normals. This is totally
unphysical but at least gives some indication of direction. Viewport
refactor and programmable shaders are needed to make this work nicer.

Store the overall result of cache reading in the DupliCache.

This is used to prevent empty dupli lists when reading the cache fails.
In that case the duplilist function will now revert to default scene
evaluation.

Extend the cache reading function to take the result archive into account.

Reorganization of file paths and input/output workflow in cache
libraries.

Having a cache archive output in each modifier is not really practical.

Now the cache library has at most 2 file paths. These are used based on
2 associated settings: source mode/path and display mode/path.

* The SOURCE mode determines whether the original scene data is used as
input or a cache archive. If the scene input is used the dupli group
objects will be evaluated as usual with Mesh data, modifiers, proxy
armatures, etc.. With cache input the data stored in a cache is used to
override the scene data instead.
* The DISPLAY mode is essentially a toggle for the whole cache modifier
stack. If it is set to 'source' the respective source data is used
without further modification. If set to 'result' the data from the
output cache archive is used, which can be generated using the bake
operator. During baking the data will be passed through the cache
modifiers to create a variation of the original source data.