SphereTree

algorithm with buffers without recustion

def getNeighbors(vec):
    for level in levels:
        if level==0:
             relevant_nodes = levels[0].nodes
        relevant_nodes_new
        for node in relevant_nodes:
             relevant_nodes_new.append( node.childsCloserThan( level[].R2OUTER ) )
        relevant_nodes = relevant_nodes_new