P.S. Disregard the part I set as strike though text in the previous reply. That was left over code from the octree version and I had to re-implement tree bounds size increase by rebuilding the tetrahexacontree due to integer coordinate powers of two alignment restrictions if the old root was made a child of a new root. So "tree root node index" is zero (always first element of array of nodes) and "tree root node index" is no longer passed to the tetrahexacontree voxel volumes raymarching shader via a uniform buffer object field (just hard coded now).