OSPRay v2.5.0

• Add native support for cones or cylinders with curves geometry of
  type OSP_DISJOINT, requiring minimum version 3.12.0 of Embree
• Replaced OSPRay's internal implementation of round linear curves by
  Embree's native implementation. Internal surfaces at joints are now
  correctly removed, leading to higher quality renderings with
  transparency, at the cost of intersection performance
• SciVis renderer improvements:
  • Colored transparency, colored shadows
  • Light sources are visible including HDRI Light environment map
• The MPI module is now distributed as part of OSPRay in the modules
  directory
  • The socket-based communication layer has been removed
• Add intensityQuantity parameter to light sources to control the
  interpretation and convertion of the intensity into a radiative
  quantity
• OSPRay now requires minimum Open VKL v0.12.0 to bring the following
  improvements:
  • Better default sampling rate for scaled volumes, improving
    performance
  • Higher robustness for axis-aligned rays
• Removed limit on the number of volumes (both overlapped and separate)
  that a ray can intersect while rendering. Now it is limited by
  available memory only.
• Move to OIDN v1.3.0 to bring the following improvements:
  • Improved denoising quality (sharpness of fine details, fewer
    noisy artifacts)
  • Slightly improved performance and lower memory consumption
• Both geometric and volumetric models can now have their child
  geometry/volume objects rebound using an object parameter
• Fix light leaking artifacts at poles of HDRI (and Sun-Sky) light
• Add sRGB conversion to ospExamples such that the color of the
  widget for backgroundColor actually matches
• Dropping support for MSVC14, new minimum compiler on Windows is
  MSVC15 (Visual Studio 2017)