AI patrol between waypoints using NavMesh

Variables: WaypointLocations (Array<Vector>), CurrentWaypointIndex (int). Pattern: EventBeginPlay → set up WaypointLocations array → MoveToNextWaypoint (custom event). MoveToNextWaypoint: GetController → CastTo<AIController> → MoveToLocation(Dest=WaypointLocations[CurrentWaypointIndex], AcceptanceRadius=100) → Bind OnMoveCompleted delegate → In callback: Increment CurrentWaypointIndex (modulo array length) → call MoveToNextWaypoint again. Alternative: Use SimpleMoveToLocation for simpler cases. Requires NavMeshBoundsVolume in scene. GetRandomReachablePointInRadius for random wander.

SimpleMoveToLocation — move AI pawn to a world location

Requires NavMesh in scene. Get AIController via GetController() on the pawn, cast to AIController.

SetStaticMesh — change static mesh on mesh component

ProjectPointToNavigation — snap a point to the nearest nav mesh

SetSkeletalMesh — change skeletal mesh on mesh component

UE5 uses SetSkeletalMeshAsset, not SetSkeletalMesh.

Physics Body

A SceneComponent with simulate-physics enabled. Driven by forces, gravity, collisions instead of explicit transforms.

Procedural mesh placement on terrain using line trace downward

Pattern for snapping object to ground: GetActorLocation → Add Vector(Z=+1000) → as TraceStart. GetActorLocation → Subtract Vector(Z=1000) → as TraceEnd. LineTraceByChannel(Start=TraceStart, End=TraceEnd, TraceChannel=Visibility) → Branch(ReturnValue=true) → BreakHitResult → SetActorLocation(NewLocation=ImpactPoint) → SetActorRotation(NewRotation=MakeRotFromZ(Normal)) [align to surface normal]. MakeRotFromZ takes a 'Z' input Vector and outputs Rotator aligned to that normal.

Ragdoll death: disable movement, enable physics on mesh

Pattern: custom OnDeath event → GetCharacterMovement → DisableMovement() → GetMesh → SetSimulatePhysics(bSimulate=true) → SetCollisionEnabled(NoCollision) on CapsuleComponent. Key: SetSimulatePhysics is called on the MESH component (SkeletalMeshComponent), NOT on the actor or CharacterMovementComponent. Also set collision profile: SetCollisionProfileName('Ragdoll') on the mesh.

CapsuleTraceSingle — capsule sweep for collision detection

AddActorWorldOffset — move actor by world-space delta