For the implementation of Enemies’ AI we decided to use Behavior Trees (BTs), Unreal Engine 4’s built-in AI system.

Even if promising alternatives are on the rise (e.g. Utility AI) we determined that using BTs was the best choice, given Epic’s vast documentation on the matter and BTs great adaptability to shooter games.

In particular the tools we used are as following:

• Behavior trees: the basic structure used in Unreal Engine for artificial intelligence.

https://docs.unrealengine.com/4.27/en-US/InteractiveExperiences/ArtificialIntelligence/BehaviorTrees/

• Navigation system: allows artificial intelligence agents to navigate the Level using pathfinding.

  https://docs.unrealengine.com/4.27/en-US/InteractiveExperiences/ArtificialIntelligence/NavigationSystem/

• EQS (Environment Query System): a feature used to collect data from the environment.

  https://docs.unrealengine.com/4.27/en-US/InteractiveExperiences/ArtificialIntelligence/EQS/

In the following sub-pages we show the BTs we implemented and explain how the nodes we used in them work.

Tasks

Services

Decorators

Composites

EQS

Where do I edit enemy properties?

How do I use Nav Link Proxies?