Mitsuba2

*July 27, 2020*

- Fix warnings, build and tests on Windows (MSVC)

*July 22, 2020*

- Instancing support via ``shapegroup`` and ``instance`` plugins (170)
- Various sampler plugins: ``stratified``, ``multijitter``, ``orthogonal``, ``ldsampler`` (187)
- ``bumpmap`` BSDF plugin (201)
- ``normalmap`` BSDF plugin
- Raytracing API improvements (209)
- Differentiable surface interaction (209)
- Add ``<path>`` XML tag (165)
- `BlenderMesh` shape plugin
- `Projector` emitter plugin
- Add support for textured area light sampling
- Add ``Mesh::eval_parameterization`` to parameterize the mesh using UV values
- Various bug fixes and other improvements

*May 19, 2020*

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

*May 18, 2020*

- `xml.load_dict()` for Mitsuba scene/object construction in Python (122)
- Scene traversal mechanism enhancement (108)
- Support premultiplied alpha correctly (104)
- Spot light plugin (100)
- Add Blender mesh constructor (40db7be)
- Irradiancemeter sensor plugin (b19985b)
- Radiancemeter sensor plugin (83)
- Distant emitter plugin (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