VDB - the better octree

I have implemented a voxel data structure similar to an octree, but with a larger branching factor (still powers of 2), that contains a hashmap at the root of the tree. It takes inspiration from the paper “VDB: High-Resolution Sparse Volumes with Dynamic Topology” by Ken Museth.

The image shows the mesh graph voxelized into a tree containing depths 2, 3 and 4 (VDB<2, 3, 4>). Depth 2 gives 64 children, 3 gives 512 children, and 4 gives 4096 children. See the following overview:

Having these higher child counts (i.e. branching factor), helps to keep the tree shallow, i.e. not as tall as an octree, where each depth only has 8 children.

The open-source implementation OpenVDB can be found here: https://www.openvdb.org. I chose to make my own version for intellectual curiousity and because my usecase is much simpler.