Fig. 4

Visualization of steps in graph pathing. (a) The hybrid graph that is generated from the point cloud. (b) Walk each node to the lowest node in its neighbors. The neighbors (e.g., light purple) of a node (e.g., purple) are bounded by nodes having edges connected to it. (c) The process in (b) is continued until the reached node is already the lowest in its vicinity. The nodes reaching the same node are then grouped, and the reached node of each group is denoted as a root node (e.g., node 1, 2, and 3). (d) Root nodes are further pruned (e.g., node 1 in (c)) and merged (e.g., node 2 and 3 in (c)). Finally, the nodes connected to invalid roots are corrected to the valid roots by shortest pathing