AI Tree
  • 🏡Home
  • ⭐Getting Started
  • Basic
    • Behaviour Tree
      • Node
      • Decorator
      • Service
    • Blackboard
      • Key (Variable)
    • Perception System
    • Environment Query System
    • Quick Start
    • User Guide
    • Shortcuts
  • Navigation
    • Building a NavMesh
  • Nodes
    • Composite
      • Sequencer
      • Selector
        • Selector
        • Random Selector
      • Parallel
        • Parallel
        • Parallel Selector
        • Parallel Complete
    • Tasks
      • Animator
        • Cross Fade
        • Cross Fade in Fixed time
        • Set Bool
        • Set Float
        • Set Integer
        • Set Trigger
      • Audio
        • Audio Mute
        • Audio Pause
        • Audio Play
        • Audio Stop
        • Play Random Sound
        • Play Sound
        • Set Audio Clip
        • Set Audio Loop
        • Set Audio Pitch
        • Set Audio Volume
      • Audio Source
        • Play Clip At Point
      • Debug
        • Debug Log
        • Debug Draw Line
        • Debug Draw Ray
      • Common
        • Wait
        • Set Key
        • Run Behaviour
        • Wait Blackboard Time
        • Finish With Result
      • EQS
        • Run EQS Query
      • Game Object
        • Activate
        • Add Component
        • Create Object
        • Destroy Component
        • Destroy Object
        • Destroy Self
        • Detach Children
        • Find
        • Find Child
        • Find Closest
        • Get Child
        • Get Child Count
        • Get Distance
        • Get Parent
        • Get Root
        • Get Tag
        • Get Name
        • Set Parent
        • Set Tag
      • Math
        • Bool Flip
        • Bool Operator
        • Float Abs
        • Float Clamp
        • Float Operator
        • Int Abs
        • Int Clamp
        • Int Operator
        • Random Bool
        • Random Float
        • Random Int
        • Sample Curve
        • Get ACos
        • Get ASin
        • Get Atan
        • Get Atan2
        • Get Atan2 From Vector2
        • Get Atan2 From Vector3
        • Get Cos
        • Get Sin
        • Get Tan
      • Movement
        • Move Towards
        • Way Point
      • NavMesh
        • Move To
        • Random Position
      • Object
        • Destroy
        • Instantiate
      • Perception System
        • Detection Signal
      • Physics
        • Box Cast
        • Capsule Cast
        • Line Cast
        • Ray Cast
        • Sphere Cast
      • Physics2D
        • Box Cast 2D
        • Capsule Cast 2D
        • Line Cast 2D
        • Ray Cast 2D
        • Sphere Cast 2D
      • Player Prefs
        • Delete All
        • Delete Key
        • Get Float
        • Get Int
        • Get String
        • Set Float
        • Set Int
        • Set String
      • Quaternion
        • Angle Axis
        • Euler
        • From To Rotation
        • Get Euler Angles
        • Inverse
        • Multiply
        • Multiply By Vector
      • Rigidbody
        • Add Explosion Force
        • Add Force
        • Add Force At Position
        • Add Relative Force
        • Add Relative Torque
        • Add Torque
        • Move Position
        • Move Rotation
        • Sleep
        • Wake Up
      • Rigidbody2D
        • Add Force 2D
        • Add Force At Position 2D
        • Add Relative Force 2D
        • Add Torque 2D
        • Move Position 2D
        • Move Rotation 2D
        • Sleep 2D
        • Wake Up 2D
      • Transform
        • Get Angle To Target
        • Get Position
        • Get Rotation
        • Inverse Transform Direction
        • Set Scale
        • Inverse Transform Point
        • Transform Direction
        • Transform Point
      • Vector2
        • Add
        • Add XY
        • Clamp Magnitude
        • Get Length
        • Get XY
        • Invert
        • Select Random
        • Set Value
        • Set XY
      • Vector3
        • Add
        • Add XYZ
        • Clamp Magnitude
        • Get Length
        • Get XYZ
        • Invert
        • Select Random
        • Set Value
        • Set XYZ
      • Unity
        • Debug
        • Send Message
        • Find Transfrom
    • Decorators
      • Blackboard Condition
      • Compare Blackboard Keys
      • Conditional Loop
      • Cone Check
      • Inverter
      • Is At Location
      • Loop
      • Has Path
      • Object Tag Condition
      • One Time Execution
      • Succeeder
      • Time Limit
  • Perception System
    • Quick Start
    • Useful Components
      • AI Perception Blackboard
      • AI Perception Source
    • Useful Nodes
  • Environment Query System
    • Quick Start
    • Items
    • Useful Components
      • EQS Tester
    • Useful Objects
      • Environment Query
        • Generator
          • Circle
          • Cone
          • Donut
          • Grid
        • Trace Mode
          • Layer
          • NavMesh
        • Tests
          • Distance
          • Dot
          • Has Path
          • Overlap
          • Slope
          • Trace
    • Useful Nodes
  • API
    • Overview
    • User Scripting
      • Custom Task
      • Custom Key
      • ToolbarItem attribute
    • Runtime
      • BehaviourTree
      • BehaviourRunner
      • Blackboard
      • Key
      • Key<T>
      • KeyQuery
      • KeyQuery<T>
      • KeyReceiver
      • KeyReceiver<T>
      • Task Node
      • Decorator Node
      • Condition Decorator
      • Observer Decorator
      • Service Node
      • Interval Service Node
      • NodeContentAttribute
      • AIPerceptionConfig
      • EQGenerator
      • EQTraceMode
      • EQTest
  • INTEGRATIONS
    • Adventure Creator
    • A* Pathfinding Project Pro
      • Move To
    • Dialogue System for Unity
      • Lua Condition Decorator
      • Lua Run
      • Dialogue Behaviour Handler
      • Blackboard Saver
      • Lua Functions
    • Mirror Network
      • Quick Start
      • Network Instantiate
      • Network Destroy
      • Network Play Clip At Point
      • Network Debug
    • Photon Network
      • Quick Start
      • Network Instantiate
      • Network Destroy
      • Network Play Clip At Point
      • Network Debug
    • PlayMaker
      • Set Runner Active
      • Set Perception Active
      • Get Blackboard Key
      • Set Blackboard Key
    • Sensor Toolkit 2
      • Sensor Config
    • Ultimate Horror FPS KIT
      • Quick Start
      • Apply Damage
      • Animator Event Disabler
    • Odin Inspector
Powered by GitBook
On this page
  1. Basic

Perception System

Basic info about perception system in AI Tree

Last updated 6 months ago

is a system that allows game characters (NPCs or AI) to perceive the environment and react to various stimuli. It simplifies AI development by providing tools for detecting other characters, objects, or sounds, and allows NPCs to make decisions based on these perceptions.

Key Aspects of the Perception System:

  1. Sensing Components:

    • The core of the Perception System consists of special components added to game characters. The primary component is AIPerception component, which handles perception and collects data about stimuli coming from different sources.

  2. Stimuli Sources:

    • Stimuli sources are objects or events that can be "perceived" by the AI character. This could be another character in the NPC’s field of view, a sound such as gunfire or footsteps, or a scent left by an object. To be detectable, an object must have the AIPerceptionSource Component added.

  3. Sensing Types:

    • Sight: One of the most commonly used perception types. AI can detect characters or objects in its line of sight.

  4. Configuring Perception:

    • For each type of perception, you can configure parameters such as range, field of view angle, perception update frequency, and sensitivity to different types of stimuli. For example, for sight, you can define the field of view angle (e.g., 90 degrees) and the sight range (e.g., 500 units).

  5. Perception Events:

    • When AI perceives an object, it can trigger an event processed in the game logic. For instance, upon detecting an enemy or hide.

  6. Sense Memory:

    • NPCs can remember objects or stimuli they perceived earlier. For example, if an enemy goes out of sight, AI can continue tracking the enemy based on the last known location.

  7. Integration with Behavior Tree:

    • The Perception System integrates closely with Behavior Trees, allowing perception to serve as triggers for initiating or altering AI behavior.

  8. Ease of Use: A user-friendly tool for adding perception to AI, reducing the complexity of development.

  9. Customizability: The ability to finely adjust perception parameters to meet specific needs.

  10. Integration with other systems: Easy integration with Behavior Trees and other AI systems.

Example of Using the Perception System:

Imagine an NPC patrolling a specific area. Using the Perception System, you can configure the NPC to notice enemies entering its line of sight and start chasing them. If the enemy escapes the NPC’s sight, the AI can remember the last known location and continue searching in that area. Additionally, if the enemy makes noise (e.g., footsteps or gunfire), the AI can turn toward the source of the sound and investigate.


The Perception System in AI Tree is a powerful and convenient tool for developing complex, adaptive AI. It allows characters to "see", and respond to stimuli in the environment, providing dynamic and realistic behavior for NPCs in the game.

Perception System