message: Additional features added to FEATURES.md
diff: +High-level description of some of the OSPRay Studio features.
  +
  +Studio provides a thin wrapper on top of the OSPRay API, as such, the rendering
  +features are better described in the, excellent, OSPRay documentation
  +(https://www.ospray.org/documentation.html)
  +
  +OBJ/MTL importer:
  +
  +- native triangle mesh and quad mesh primitives
  +- basic OBJ materials, with extension for any OSPRay material via "type" keyword
  +- texture and "texture transformations" supported on all OSPRay texturable material parameters via "map_" parameter prefix
  +- support for UDIM texture tiles with common "*1001*" filenaming convension
  +
  glTF importer:
  -- mesh, vanilla materials, animation (including camera), skinning
  -- KHR_lights_punctual
  +- mesh and points primitives, vanilla materials, animation (including camera), skinning
  +- KHR_lights_punctual: "directional", "point", "spot"; custom extension for OSPRay "sunSky" and "hdri" light types
  - KHR_materials_pbrSpecularGlossiness: "diffuseFactor", "diffuseTexture", "specularFactor", "glossinessFactor"
  - KHR_materials_clearcoat: "clearcoatFactor", "clearcoatRoughnessFactor", "clearcoatTexture", "clearcoatRoughnessTexture", "clearcoatNormalTexture"
  - KHR_materials_transmission: "transmissionFactor", "transmissionTexture"
  @@ -17,8 +30,17 @@ glTF importer:
  - EXT_cameras_sensor, respecting
  - "imageSensor": "pixels", "pixelSize"
  - "lens": "focalLength", "apertureRadius", "focusDistance", "centerPointShift"
  +- support for UDIM texture tiles with common "*1001*" filenaming convension
  +
  +PCD importer:
  +
  +- file importer for common "Point Cloud Data" (https://pointclouds.org/) format
  +
  +Volume rendering:
  -PCD importer
  +- importers for raw structured, raw spherical, particle volumes, and OpenVDB file formats
  +- scenegraph support to structure, unstructured, particle volumes, and vdb data formats
  +- controls for transfer functions and implicit iso-surfaces, as supported by OSPRay and OpenVKL
  Meta data export, using plugin "metadata" via `ospStudio batch -p metadata -m ...`:
  @@ -28,8 +50,22 @@ Meta data export, using plugin "metadata" via `ospStudio batch -p metadata -m ..
  batch mode:
  +- scriptable headless rendering for offline images
  - setting animation speed (fps)
  - selecting frames (sub-range) to be rendered
  - selecting camera (if multiple specified in glTF)
  - selecting scene configuration from command line
  - setting rendering parameters (maxContribution, accumLimit, variance)
  +
  +python bindings:
  +
  +- the scene graph is exposed via pybind11 binding for full scriptable support
  +
  +JSON scene file format:
  +
  +- the scenegraph state may loaded/saved to a JSON file
  +
  +Extendable via plugins:
  +
  +- plugin mechanism allows extension of file importer, scene graph internals, and UI widgets/appearance
  +- several of the plugins under development are featured on the website
  