Troll Fight

Troll Boss Encounter

Engine: Unreal Engine 5 | Tools: Blueprint, AI Perception, Behavior Tree, BlackBoard, Animation State Machine

Sight is handled using UE5’s Pawn Sensing component with line-of-sight detection.

  1. Hearing is implemented through custom Blueprint events. Any Blueprint can emit a noise event, allowing spells and attacks to alert the troll if it's within hearing range.

  2. Damage triggers a temporary “awareness” of the player’s location even without sight, allowing the AI to follow for a short period before falling back to investigation behavior.

Summary:

  • Built using Unreal’s Behavior Tree and Blackboard systems.

  • States are managed with a custom AI State Enum: Patrol, Investigate, Follow, Attack.

  • Patrol is handled through spline movement.

  • Transitions are triggered by AI Perception (sight, hearing) or damage taken.

  • Loss of sight causes a fallback to Investigate, and eventually to Patrol if the player isn’t found.

  • The attack uses animation notifies to enable and disable the weapon’s hitbox at the correct time.

Full Fight

Summary:

  • The troll is spawned when the player walks over a trigger volume near the castle ruins.

  • It patrols along a spline path until a sense is triggered.

  • The troll has four behavior states:

    • Patrol

    • Investigate (hearing-based)

    • Follow (when player is seen or after taking damage)

    • Attack (when within 150 units)

  • The troll uses a single club swing attack. A weapon-based hitbox activates during the animation.

  • If the hitbox collides with the player, damage is applied.