Below is a quick rundown of some of the Actors you will most commonly use or come across while developing games with Unreal Engine to familiarize you with what they are and why you would use them.
| Type | Icon | Description | |||||||||
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| Mesh & Geometry Actor Types | |||||||||||
| StaticMeshActor |  |
The Static Mesh Actor is a simple type of Actor that displays a mesh in the scene. Even though the name implies the Actor is static - or cannot move - the static part of the name refers to the type of mesh, a StaticMesh, that is used. These meshes are static in that their geometry does not change. The actual Actor can move or be modified in other ways during play, however. These Actors are generally used as world geometry and decorative meshes to create the environments of the level. See Static Mesh Actors for more detailed usage information. | |||||||||
| Brush |  |
The Brush Actor is a basic type of Actor that displays simple 3D geometry in the scene. These Actors can be modified using the Geometry Editing mode in the Level Editor. BrushActors (or just Brushes) are commonly used for quickly prototyping environments and blocking out levels for testing gameplay. | |||||||||
| SkeletalMeshActor |  |
The Skeletal Mesh Actor is a type of Actor that displays an animated mesh, or a SkeletalMesh, whose geometry can be deformed - generally through the use of animation sequences created and exported from external 3D animation applications. These Actors are usually used for things like characters or other living creatures as well as complex machinery; anything that needs to deform or display other complex motion. These are also often used in conjunction with Matinee to create cinematic sequences | |||||||||
| Gameplay Actor Types | |||||||||||
| PlayerStart |  |
A Player Start is an Actor that is placed in the level to designate where the player should start out when the game begins. | |||||||||
| Triggers |    |
Triggers are Actors that are used to cause an event to occur when they are interacted with by some other object in the level. In other words, they are used to trigger events in response to some other action in the level. All of the default Triggers are generally the same, differing only in the shape of the area of influence - box, capsule, and sphere - used by the Trigger to detect if another object has activated it.
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| MatineeActor |  |
Matinee Actors enable you to animate the properties of Actors over time via the Matinee animation tool, to create either dynamic gameplay or cinematic in-game sequences. The system is based on the use of specialized animation tracks in which you can place keyframes to set the values of certain properties of the Actors in the level. The Matinee animation tool is similar to the non-linear editors used for video editing, making it familiar to video professionals. See Matinee and Cinematics for more detailed usage information. | |||||||||
| Light Actor Types | |||||||||||
| PointLight |  |
Point Lights work much like a real world light bulb, emitting light in all directions from the light bulb's tungsten filament. However, for the sake of performance, Point Lights are simplified down emitting light equally in all directions from just a single point in space. The Point Light when placed can be set to one of three Mobility settings:
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| SpotLight |  |
A Spot Light emits light from a single point in a cone shape. Users are given two cones to shape the light - the Inner Cone Angle and Outer Cone Angle. Within the Inner Cone Angle, the light achieves full brightness. As you go from the extent of the inner radius to the extents of the Outer Cone Angle, a falloff takes place, creating a penumbra, or softening around the Spot Light's disc of illumination. The Radius of the light defines the length of the cones. More simply, this will work like a flash light or stage can light. Like other lights, a Spot Light can be set to one of three Mobility settings:
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| DirectionalLight |  |
The Directional Light simulates light that is being emitted from a source that is infinitely far away. This means that all shadows cast by this light will be parallel, making this the ideal choice for simulating sunlight. The Directional Light when placed can be set to one of three Mobility settings:
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| Effects Actor Types | |||||||||||
| ParticleEmitter |  |
A Particle Emitter is an Actor that is used to create effects such as smoke, fire, sparks, and more by spawning particles in the form of sprites (camera-facing planes) or meshes. The actual behavior of the particles is defined in and controlled by special assets called Particle Systems which are created in the Content Browser and edited in the Cascade Particle Editor | |||||||||
| Sound Actor Types | |||||||||||
| AmbientSound |  |
Ambient Sound Actors are used to play sounds - in the form of Sound Cues - within the world. These sounds can be looping or non-looping and have spatialization and attenuation, though all of this must be set up in the SoundCue and is not exposed on the Ambient Sound Actor itself. |
