Artificial Intelligence Tools - Heuristic Function

The AI Tools package is an extension for Stencyl development environment. It is a general-purpose graphs toolset, which includes an implementation of A* pathfinding.

Please see main page for more information.

The heuristic function is used in the A* implementation to estimate the minimum cost to reach the goal from any point on the graph. A thorough discussion can be found here: (http://theory.stanford.edu/~amitp)^[1]. The AI tools extension provides four options:

Euclidean Norm is the default option. The distance between two nodes is calculated using the standard "distance formula" most of us learned in algebra class.

Taxicab Norm computes the distance as the sum of "steps left/right" and "steps up/down". The name derives from how distances between buildings on a city street grid are calculated.

Maximum Norm computes the distance as the greater of the horizontal distance (difference between columns) and vertical distance (difference between the rows).

Dijkstra will always return 0. As per [1], this will guarantee the best path is found, at a cost of speed.

Custom heuristics can be easily implemented by modifying the code. The function costEstimate can be found in the AStar class.