Implementation of the Octree which can be queried from the CUDA device code.
The implementation is based on the paper: J. Behley, V. Steinhage, A.B. Cremers. Efficient Radius Neighbor Search in Three-dimensional Point Clouds, Proc. of the IEEE International Conference on Robotics and Automation (ICRA), 2015.
Ideas from CPU Octree implementation at https://github.com/jbehley/octree are used. That implementation is more optimal and feature rich in case CUDA is not used.