ai-and-navigation

Create an AIController subclass, set it as the pawn's AIControllerClass with AutoPossessAI enabled, then call MoveToActor or MoveToLocation. The level needs a NavMeshBoundsVolume so the RecastNavMesh can compute paths, and the pawn needs a movement component to follow them.

Create a UBlackboardData asset with typed keys, assign it to a UBehaviorTree asset, then call RunBehaviorTree in the controller's OnPossess. Custom C++ tasks subclass UBTTaskNode and return Succeeded, Failed, or InProgress from ExecuteTask.

MoveTo fails silently when no NavMeshBoundsVolume exists, the navmesh was not rebuilt after geometry changes, or the pawn lacks a movement component. Press P in the editor viewport to visualize nav coverage and verify the green walkable mesh exists.

StateTree is the modern direction for new projects on UE 5.4+, offering explicit state transitions and lightweight struct-based tasks. Behavior Trees remain better for large existing codebases and many simple AI sharing one tree asset, and both systems can coexist.

Add a UAIPerceptionComponent to the AIController with a UAISenseConfig_Sight configured via ConfigureSense, then bind OnTargetPerceptionUpdated. The target actor needs a UAIPerceptionStimuliSourceComponent registered for the sight sense to be detectable.

EQS scores and ranks candidate locations or actors using generators and tests, returning the best match for queries like cover from the player or nearest flanking position. Run it from C++ with FEnvQueryRequest::Execute or from a Behavior Tree using the built-in RunEQSQuery task.