Actor Hierarchy

Author:Tim Johnson

Introduction

This article gives a high-level technical overview of Reality Engine's Actor hierarchy and message processing.

Actor

Actor forms the base class for all items existing in the world. Whether these are lights, geometry, players, effects, scripts, weapons, or sound sources, they all derive from Actor. For those familiar with Unreal Script, the Actor class hierarchies are analogous.

Classes in bold are in C++, classes with 'M' prefix are managed C++/CLI wrappers. All other classes are C#.

Actor
   +- NetworkActor
        +- SkyController
   +- Prefab
   +- PrefabInstance
   +- IndoorVolume
   +- WaterSurface
   +- MActor
        +- ActorSpawner
        +- AnimatedModel
        +- DemoPlayer
        +- DestroyableNotNetworked
        +- Effect_LightBeam
        +- Effect_ParticleSystem
             +- Precipitation
        +- GameConfig
        +- MusicPlayer
        +- MNetworkActor
             +- AssaultPoint
             +- Destroyable
                  +- Grenade
                  +- InventoryItem
                       +- Weapon
                            +- AssaultRifle
                            +- PhysicsGun
                  +- NetRigidBody
                       +- AttachedBody
                       +- DestroyedTruckXXX
                  +- Pawn
                       +- Player
                            +- PlayerBot
                  +- Vehicle
                       +- Truck
             +- GameState
             +- PickupItem
                  +- PickupAmmo
                  +- PickupHealth
                  +- PickupQuadDamage
        +- PlayerSpawnPoint
        +- PrecacheClasses
        +- RotatingModel
        +- SoundSource
             +- AmbientSoundSource
   +- Light
        +- MLight
             +- SkyColorLight
             +- TimedLight

NetworkActor

Networked Actor.

Prefab

Geometry that will not move during gameplay. Fundamental building block for scenes.

PrefabInstance

Same as prefab, but instanced from an on-disk model file. Any number of PrefabInstances point to a single instance of the geometry in memory with different rotations and locations.

World

World is the hub for processing all game logic, including updating Actors, running scripts, applying collision and physics, processing input, and (optionally) rendering.