Probabilistic Smart Terrain

“Smart terrain” is a very efficient algorithm used in many games (such as The Sims), in which objects that meet needs transmit signals to non-player characters with those needs, influencing the character to move towards those objects. We describe how probabilities can be added to this algorithm, allowing an object to broadcast that it “may” meet a need with a given probability, as well as how expected distances to an object that meets a need can be used to allow the non-player characters to make plausible decisions about which direction to move. We also describe a set of benchmarks for realistic behavior in an uncertain environment, how the algorithm can factor in learned knowledge of whether an object actually does meet a need, and how probabilistic smart terrain can be implemented and integrated into games.