Embree v3.10.0 Release

• Added EMBREE_COMPACT_POLYS CMake option which enables double indexed triangle and quad
  leaves to reduce memory consumption in compact mode by an additional 40% at about
  15% performance impact. This new mode is disabled by default.
• Compile fix for oneTBB 2021.1-beta05
• Releases upgrade to TBB 2020.2
• Compile fix for ISPC v1.13.0
• Adding RPATH to libembree.so in releases
• Increased required CMake version to 3.1.0
• Made instID member for array of pointers ray stream layout optional again.

Embree v3.9.0

• Added round linear curve geometry support. In this mode a real geometric surface for curves
  with linear basis is rendered using capped cones with spherical filling between
  the curve segments.
• Added rtcGetSceneDevice API function, that returns the device a scene got created in.
• Improved performance of round curve rendering by up to 1.8x.
• Bugfix to sphere intersection filter invokation for back hit.
• Fixed wrong assertion that triggered for invalid curves which anyway get filtered out.
• RelWithDebInfo mode no longer enables assertions.
• Fixed an issue in FindTBB.cmake that caused compile error with Debug build under Linux.
• Embree releases no longer provide RPMs for Linux. Please use the RPMs coming with the package
  manager of your Linux distribution.

Embree v3.8.0 Release

New Features:

• Added collision detection support for user geometries (see rtcCollide API function)
• Passing geomID to user geometry callbacks.

Fixed Issues:

• Bugfix in AVX512VL codepath for rtcIntersect1
• For sphere geometries the intersection filter gets now invoked for
  front and back hit.
• Fixed some bugs for quaternion motion blur.
• RTCIntersectContext always non-const in Embree API
• Made RTCHit aligned to 16 bytes in Embree API

Embree v3.7.0 Release

• Added quaternion motion blur for correct interpolation of rotational transformations.
• Fixed wrong bounding calculations when a motion blurred instance di
  instantiate a motion blurred scene.
• In robust mode the depth test consistently uses tnear <= t <= tfar now in order
  to robustly continue traversal at a previous hit point
  in a way that guarentees reaching all hits, even hits at the same place.
• Fixed depth test in robust mode to be precise at tnear and tfar.
• Added next_hit tutorial to demonstrate robustly collecting all hits
  along a ray using multiple ray queries.
• Implemented robust mode for curves. This has a small performance impact but
  fixes bounding problems with flat curves.
• Implemented issue with motion blur builder where number of time segments
  for SAH heuristic were counted wrong due to some numerical issues.
• Fixed an accuracy issue with rendering very short fat curves.
• rtcCommitScene can now get called during rendering from multiple threads
  to lazily build geometry. When TBB is used this causes a much lower overhead
  than using rtcJoinCommitScene.
• Geometries can now get attached to multiple scenes at the same time, which
  simplifies mapping general scene graphs to API.
• Updated to TBB 2019.9 for release builds.
• Fixed a bug in the BVH builder for Grid geometries.
• Added macOS Catalina support to Embree releases.

Embree v3.6.1 Release

• Restored binary compatibility between Embree 3.6 and 3.5 when single-level instancing is used.
• Fixed bug in subgrid intersector.
• Removed point query alignment in ISPC header.

Embree v3.6.0 Release

• Added Catmull-Rom curve types.
• Added support for multi-level instancing.
• Added support for point queries.
• Fixed a bug preventing normal oriented curves being used unless timesteps were specified.
• Fixed bug in external BVH builder when configured for dynamic build.
• Added support for new config flag "user_threads=N" to device initialization
  which sets the number of threads used by TBB but created by the user.
• Fixed automatic vertex buffer padding when using rtcSetNewGeometry API function.

Embree v3.6.0-beta.0 Release

• Added Catmull-Rom curve types.
• Added support for multi-level instancing.
• Added support for point queries.
• Fixed a bug preventing normal oriented curves being used unless timesteps were
  specified.
• Fixed bug in external BVH builder when configured for dynamic build.
• Added support for new config flag "user_threads=N" to device initialization
  which sets the number of threads used by TBB but created by the user.
• Fixed automatic vertex buffer padding when using rtcSetNewGeometry API function.

Embree v3.5.2

• Added EMBREE_ISA_NAMESPACE cmake option that allows to put all Embree API functions
  inside a user defined namespace.
• Added EMBREE_LIBRARY_NAME cmake option that allows to rename the Embree library.
• When Embree is compiled as static library, EMBREE_STATIC_LIB has no longer to get
  defined before including the Embree API headers.
• Added CPU frequency_level device configuration to allow an application to specify the
  frequency level it wants to run on. This forces Embree to not use optimizations that
  may reduce the CPU frequency below that level. By default Embree is configured to the
  the AVX-heavy frequency level, thus if the application uses solely non-AVX code, configuring
  the Embree device with "frequency_level=simd128" may give better performance.
• Fixed a bug in the spatial split builder which caused it to fail
  for scenes with more than 2^24 geometries.

Embree v3.5.1

• Fixed ray/sphere intersector to work also for non-normalized rays.
• Fixed self intersection avoidance for ray oriented discs when non-normalized rays were used.
• Increased maximal face valence for subdiv patch to 64 and reduced stack size requirement for subdiv patch evaluation.

Embree v2.17.7

• Fixed frequency issue for Skylake server CPUs.