OSPRay v2.0.0

• New major revision of OSPRay brings API breaking improvements over
  v1.x. See doc/ospray2_porting_guide.md for a deeper description of
  migrating from v1.x to v2.0 and doc/api.md for the latest API
  documentation
  • ospRenderFrame now takes all participating objects as
    function parameters instead of setting some as renderer params
  • ospRenderFrame is now asynchronous, where the task is managed
    through a returned OSPFuture handle
  • The heirarchy of objets in a scene are now more granular to
    aid in scene construction flexibility and reduce potential
    object duplication
  • Type-specific parameter setting functions have been consolidated
    into a single ospSetParam API call
  • C++ wrappers found in ospray_cpp.h now automatically track
    handle lifetimes, therefore applications using them do not need
    to use ospRelease (or the new ospRetain) with them: see
    usage example in apps/tutorials/ospTutorial.cpp
  • Unused parameters are reported as status messages when
    logLevel is >= 1 (most easily set by enabling OSPRay debug on
    initialization)
• New utility library which adds functions to help with new API
  migration and reduction of boilerplate code
  • Use ospray_util.h to access these additional functions
  • All utility functions are implemented in terms of the core API
    found in ospray.h, therefore they are compatible with any
    device backend
• Introduction of new Intel® Open Volume Kernel Library (Open VKL)
  for greatly enhanced volume sampling and rendering features and
  performance
• Added direct support for Intel® Open Image Denoise as an optional
  module, which adds a denoiser type to ospNewImageOperation
• OSPRay now requires minimum Embree v3.7.0
• New CMake superbuild available to build both OSPRay's dependencies
  and OSPRay itself
  • Found in scripts/superbuild
  • See documentation for more details and example usage
• The ospcommon library now lives as a stand alone repository and
  is required to build OSPRay
• The MPI module is now a separate repository, which also contains all
  MPI distributed rendering documentation
• Log levels are now controled with enums and named strings (where applicable)
  • A new flag was also introduced which turns all OSP_LOG_WARNING messages
    into errors, which are submitted to the error callback instead of the
    message callback
  • Any unused parameters an object ignores now emit a warning message
• New support for volumes in the pathtracer
  • Several parameters are available for performance/quality
    trade-offs for both photo-realistic and scientific visualization
    use cases
• Simplification of the SciVis renderer
  • Fixed AO lighting and simple ray marched volume rendering for
    ease of use and performance
• Overlapping volumes are now supported in both the pathtracer and scivis
  renderers
• New API call for querying the bounds of objects (OSPWorld,
  OSPInstance, and OSPGroup)
• Lights now exist as a parameter to the world instead of the renderer
• Removal of slices geometry. Instead, any geometry with volume
  texture can be used for slicing
• Introduction of new boxes geometry type
• Expansion of information returned by ospPick
• Addition of API to query version information at runtime
• Curves now supports both, per vertex varying radii as in vec4f[] vertex.position_radius and constant radius for the geometry with
  float radius. It uses OSP_ROUND type and OSP_LINEAR basis by
  default to create the connected segments of constant radius. For per
  vertex varying radii curves it uses Embree curves.
• Add new Embree curve type OSP_CATMULL_ROM for curves
• Minimum required Embree version is now 3.7.0
• Removal of cylinders and streamlines geometry, use curves
  instead
• Triangle mesh and Quad mesh are superseded by the mesh geometry
• Applications need to use the various error reporting methods to
  check wether the creation (via ospNew...) of objects failed; a
  returned NULL is not a special handle anymore to signify an error
• Changed module init methods to facilitate version checking:
  extern "C" OSPError ospray_module_init_<name>(int16_t versionMajor, int16_t versionMinor, int16_t versionPatch)
• The map_backplate texture is supported in all renderers and does
  not hide lights in infinity (like the HDRI light) anymore;
  explicitely make lights invisible if this is needed
• Changed the computation of variance for adaptive accumulation to be
  independent of TILE_SIZE, thus varianceThreshold needs to be
  adapted if using a different TILE_SIZE than default 64
• OSPGeometricModel now has the option to index a renderer-global material
  list that lives on the renderer, allowing scenes to avoid renderer-specific
  materials
• Object type names and parameters all now follow the camel-case convention
• New ospExamples app which consolidates previous interactive apps into one
• New ospBenchmark app which implements a runnable benchmark suite
• Known issues:
  • ISPC v1.11.0 and Embree v3.6.0 are both incompatible with OSPRay
    and should be avoided (OSPRay should catch this during CMake
    configure)