Embree

- Added new normal-oriented curve primitive for ray tracing of grass-like
structures.
- Added new grid primitive for ray tracing tessellated and displaced surfaces
in very memory efficient manner.
- Fixed bug of ribbon curve intersector when derivative was zero.
- Installing all static libraries when EMBREE_STATIC_LIB is enabled.
- Added API functions to access topology of subdivision mesh.
- Reduced memory consumption of instances.
- Improved performance of instances by 8%.
- Reduced memory consumption of curves by up to 2x.
- Up to 5% higher performance on AVX-512 architectures.
- Added native support for multiple curve basis functions. Internal
basis conversions are no longer performed, which saves additional
memory when multiple bases are used.
- Fixed issue with non thread safe local static variable initialization
in VS2013.
- Bugfix in rtcSetNewGeometry. Vertex buffers did not get properly
overallocated.
- Replaced ImageMagick with OpenImageIO in the tutorials.

- Switched to a new version of the API which provides improved
flexibility but is not backward compatible. Please see "Upgrading
from Embree 2 to Embree 3" section of the documentation for upgrade
instructions. In particular, we provide a Python script that performs
most of the transition work.
- User geometries inside an instanced scene and a top-level scene no
longer need to handle the instID field of the ray differently. They
both just need to copy the context.instID into the ray.instID field.
- Support for context filter functions that can be assigned to a ray
query.
- User geometries can now invoke filter functions using the
rtcFilterIntersection and rtcFilterOcclusion calls.
- Higher flexibility through specifying build quality per scene and
geometry.
- Geometry normal uses commonly used right-hand rule from now on.
- Added self-intersection avoidance to ribbon curves and lines.
Applications do not have to implement self-intersection workarounds
for these primitive types anymore.
- Added support for 4 billion primitives in a single scene.
- Removed the RTC_MAX_USER_VERTEX_BUFFERS and RTC_MAX_INDEX_BUFFERS
limitations.
- Reduced memory consumption by 192 bytes per instance.
- Fixed some performance issues on AVX-512 architectures.
- Individual Contributor License Agreement (ICLA) and Corporate
Contributor License Agreement (CCLA) no longer required to
contribute to the project.

- Improved watertightness of robust mode.
- Fixed floating point exception in static variable initialization.
- Fixed AVX512 compile issue with GCC 6.1.1.

- Fixed AVX512 compile issue with GCC 7.
- Fixed issue with not thread safe local static variable
initialization in VS2013.
- Fixed bug in the 4 and 8-wide packet intersection of instances with
multi-segment motion blur on AVX-512 architectures.
- Fixed bug in rtcOccluded4/8/16 when only AVX-512 ISA was enabled.

- Fixed GCC compile warning in debug mode.
- Fixed bug of ribbon curve intersector when derivative was zero.
- Installing all static libraries when EMBREE_STATIC_LIB is enabled.

- Made BVH build of curve geometry deterministic.