Blender Git Loki

Cycles: fixed some warnings in embree integration

Cycles: prevented interactive rendering from crashing with Embree when objects are made invisible - RTCScenes now only get deleted by the top level BVH

Cycles: improved defaults for embree option, enable embree in the UI only when a CPU device is selected

Cycles: Added support for BVH refitting/dynamic meshes with embree

Cycles: improvements to hair rendering using embree

Cycles: embree hair now uses curve and not line segments, no more intersection filters for closest hit queries

Cycles: added memory and progress callbacks to embree

Cycles: Added volume support for embree

Cycles: Embree support for ribbon line segments and subsurface scattering

Cycles: Embree accelerator now supports instanced triangle meshes

Cycles: Progress with embree integration, still incomplete however

Cycles: more work on embree integration - triangle meshes now support deformation motion blur

Cycles: Laid some foundation for embree ray accelerator: flags, UI and CMake

Use material slot index instead of a direct Material pointer.

A Material pointer would be a nicer way to assign a hair material,
but unfortunately that does not work well with the context-based material
lookup of the node editor. There is no selection of an "active" modifier,
so the node editor will never display the material (unless it is placed
into a material stack as well).

Merge branch 'blender2.8' into greasepencil-object

Cycles: Use ShaderEvalIntent more to pass flag, closures, and eval_task less

This makes it so that path_flag and max_closures are not passed to shader eval
functions, instead a limited number of ShaderEvalIntents are used. This also
removes the need for ShaderEvalTask in the mega kernel and simplifies the
code a bit.

Use weight in Hook modifier

Material pointer in hair systems.

Simplified API for generating hair follicles with a fixed max count.

The final count is inversely proportional to the min_distance, so using that
as a user variable is difficult to control. Instead we just use the overall
count as the single variable now.

The actual final count will be less than this maximum count, because the
theoretical limit is never reached in practice. The min. distance could also
be stored as a result of the hair generation as feedback for the user.

Change Hook modifier default parameters