The tech is described here:
https://umbragame.com/the-tech-behind-wolcen-part1-svoti/
http://on-demand.gputechconf.com/gtc/2012/presentations/S0610-Octree-Based-Sparse-Voxelization-for-RT-Global-Illumination.pdf
This could be very useful for faster real-time computation in BR and cycles.