xTrek: An Influence-Aware Technique for Dijkstra’s and A Pathfinders

Finding a path (in black) from the top-left node to the bottom-right node of a 50 × 50 grid using the constraint-aware navigation algorithm (CAN): (a) without attractors and repulsors, the search space only covers neutral nodes (in cyan) along or close to the path (in black); (b) with 2 attractors, the search space almost covers the entire map, including neutral nodes (in cyan) and attractor nodes (in red-to-yellow blended with cyan); (c) with 2 repulsors, the search space covers neutral nodes (in cyan) found on the way to the goal node, and part of the repulsor nodes (those in purple blue as a result of blending light dark-to-light lilac with cyan); (d) with 2 attractors and 2 repulsors, the search space covers the entire map, including neutral nodes (in cyan), attractor nodes (in red-to-yellow blended with cyan), and repulsor nodes (in purple blue as a result of blending light dark-to-light lilac with cyan). Nodes in cyan or blended with cyan represent visited nodes, that is, nodes in the open and closed lists.