Mitsuba v2.2.1

Mitsuba v2.2.0

Mitsuba v2.1.0

- Switch to OptiX 7 for GPU ray tracing backend (mitsuba-renderer#88)
- Mesh memory layout redesign (mitsuba-renderer#88)
- Custom shape support for OptiX raytracing backend (mitsuba-renderer#135)
- xml.dict_to_xml() for writing XML scene file from Python (mitsuba-renderer#131)

Mitsuba v2.0.1

- xml.load_dict() for Mitsuba scene/object construction in Python (mitsuba-renderer#122)
- Scene traversal mechanism enhancement (mitsuba-renderer#108)
- Support premultiplied alpha correctly (mitsuba-renderer#104)
- Spot light plugin (mitsuba-renderer#100)
- Add Blender mesh constructor (40db7be)
- Irradiancemeter sensor plugin (b19985b)
- Radiancemeter sensor plugin (mitsuba-renderer#83)
- Distant emitter plugin (mitsuba-renderer#60)
- Custom shape support for Embree raytracing backend (2c1b63f)
- Add ability to specify Python default variant (4472b55)
- Add pytest -m "not slow" option (4597466)
- Moment integrator and Z-tests (74b2bf6)
- Spatially-varying `alpha` for roughconductor and roughdielectric (cac8741)
- Various bug fixes and other improvements

Initial public release