Open3d

- CUDA support 10.1 -> 11.0. Tensorflow 2.3.1 -> 2.4.1. PyTorch 1.6.0 -> 1.7.1 (PR 3049). This requires a custom PyTorch wheel from <https://github.com/isl-org/open3d_downloads/releases/tag/torch1.7.1> due to PyTorch issue #52663

- RealSense SDK v2 integrated for reading RS bag files (PR 2646)
- Tensor based RGBDImage class, Python bindings for Image and RGBDImage
- RealSense sensor configuration, live capture and recording (with example and tutorial) (PR 2748)
- Add mouselook for the legacy visualizer (PR 2551)
- Add function to randomly downsample pointcloud (PR 3050)
- Allow TriangleMesh with textures to be added (PR 3170)
- Python property of open3d.visualization.rendering.Open3DScene `get_view` has been renamed to `view`.
- Added LineSet::CreateCameraVisualization() for creating a simple camera visualization from intrinsic and extrinsic matrices (PR 3255)

- Fixes bug for preloading libc++ and libc++abi in Python
- Added GUI widgets and model-viewing app
- Fixes travis for race-condition on macOS
- Fixes appveyor configuration and to build all branches
- Updated travis.yml to support Ubuntu 18.04, gcc-7, and clang-7.0
- Contributors guidelines updated
- Avoid cstdlib random generators in ransac registration, use C++11 random instead.
- Fixed a bug in open3d::geometry::TriangleMesh::ClusterConnectedTriangles.
- Added option BUILD_BENCHMARKS for building microbenchmarks
- Extend Python API of UniformTSDFVolume to allow setting the origin
- Corrected documentation of PointCloud.h
- Added ISS Keypoint Detector
- Added an RPC interface for external visualizers running in a separate process
- Added `maximum_error` and `boundary_weight` parameter to `simplify_quadric_decimation`
- Remove support for Python 3.5
- Development wheels are available for user testing. See [Getting Started](https://www.open3d.org/docs/latest/getting_started.html) page for installation.
- PointCloud File IO support for new tensor data types.
- New PointCloud format support: XYZI (ASCII).
- Fast compression mode for PNG writing. (Issue 846)
- Ubuntu 20.04 (Focal) support.
- Added Line3D/Ray3D/Segment3D classes with plane, point, closest-distance, and AABB tests
- Updated Open3D.h.in to add certain missing header files
- Add Open3D-ML to Open3D wheel
- Fix a bug in PointCloud file format, use `float` instead of `float_t`
- Add per-point covariance member for geometry::PointCloud class.
- Add Generalized ICP implementation.

- Version bump to 0.9.0