List of Bevy Builtins

This page is a quick condensed listing of all the important things provided by Bevy.

• SystemParams
• Assets
• File Formats
• GLTF Asset Labels
• Shader Imports
• wgpu Backends
• Schedules
• Run Conditions
• Plugins
• Bundles
• Resources (Configuration)
• Resources (Engine User)
  • Main World
  • Render World
  • Low-Level wgpu access
• Resources (Input)
• Events (Input)
• Events (Engine)
• Events (System/Control)
• Components

SystemParams

These are all the special types that can be used as system parameters.

(List in API Docs)

In regular systems:

• Commands: Manipulate the ECS using commands
• Query<T, F = ()> (can contain tuples of up to 15 types): Access to entities and components
• Res<T>: Shared access to a resource
• ResMut<T>: Exclusive (mutable) access to a resource
• Option<Res<T>>: Shared access to a resource that may not exist
• Option<ResMut<T>>: Exclusive (mutable) access to a resource that may not exist
• Local<T>: Data local to the system
• EventReader<T>: Receive events
• EventWriter<T>: Send events
• &World: Read-only direct access to the ECS World
• ParamSet<...> (with up to 8 params): Resolve conflicts between incompatible system parameters
• Deferred<T>: Custom "deferred mutation", similar to Commands, but for your own things
• RemovedComponents<T>: Removal detection
• Gizmos: A way to draw lines and shapes on the screen for debugging and dev purposes
• Diagnostics: A way to report measurements/debug data to Bevy for tracking and visualization
• SystemName: The name (string) of the system, may be useful for debugging
• ParallelCommands: Abstraction to help use Commands when you will do your own parallelism
• WorldId: The World ID of the world the system is running on
• ComponentIdFor<T>: Get the ComponentId of a given component type
• Entities: Low-level ECS metadata: All entities
• Components: Low-level ECS metadata: All components
• Bundles: Low-level ECS metadata: All bundles
• Archetypes: Low-level ECS metadata: All archetypes
• SystemChangeTick: Low-level ECS metadata: Tick used for change detection
• NonSend<T>: Shared access to Non-Send (main thread only) data
• NonSendMut<T>: Exclusive access to Non-Send (main thread only) data
• Option<NonSend<T>>: Shared access to Non-Send (main thread only) data that may not exist
• Option<NonSendMut<T>>: Exclusive access to Non-Send (main thread only) data that may not exist
• StaticSystemParam: Helper for generic system abstractions, to avoid lifetime annotations
• tuples containing any of these types, with up to 16 members

In exclusive systems:

• &mut World: Full direct access to the ECS World
• Local<T>: Data local to the system
• SystemState<P>: Emulates a regular system, allowing you to easily access data from the World. P are the system parameters.
• QueryState<Q, F = ()>: Allows you to perform queries on the World, similar to a Query in regular systems.

Your function can have a maximum of 16 total parameters. If you need more, group them into tuples to work around the limit. Tuples can contain up to 16 members, but can be nested indefinitely.

Systems running during the Extract schedule can also use Extract<T>, to access data from the Main World instead of the Render World. T can be any read-only system parameter type.

Assets

(more info about working with assets)

These are the Asset types registered by Bevy by default.

• Image: Pixel data, used as a texture for 2D and 3D rendering; also contains the SamplerDescriptor for texture filtering settings
• TextureAtlas: 2D "Sprite Sheet" defining sub-images within a single larger image
• Mesh: 3D Mesh (geometry data), contains vertex attributes (like position, UVs, normals)
• Shader: GPU shader code, in one of the supported languages (WGSL/SPIR-V/GLSL)
• ColorMaterial: Basic "2D material": contains color, optionally an image
• StandardMaterial: "3D material" with support for Physically-Based Rendering
• AnimationClip: Data for a single animation sequence, can be used with AnimationPlayer
• Font: Font data used for text rendering
• Scene: Scene composed of literal ECS entities to instantiate
• DynamicScene: Scene composed with dynamic typing and reflection
• Gltf: GLTF Master Asset: index of the entire contents of a GLTF file
• GltfNode: Logical GLTF object in a scene
• GltfMesh: Logical GLTF 3D model, consisting of multiple GltfPrimitives
• GltfPrimitive: Single unit to be rendered, contains the Mesh and Material to use
• AudioSource: Audio data for bevy_audio
• FontAtlasSet: (internal use for text rendering)
• SkinnedMeshInverseBindposes: (internal use for skeletal animation)

File Formats

These are the asset file formats (asset loaders) supported by Bevy. Support for each one can be enabled/disabled using cargo features. Some are enabled by default, many are not.

Image formats (loaded as Image assets):

Audio formats (loaded as AudioSource assets):

3D asset (model or scene) formats:

Shader formats (loaded as Shader assets):

Font formats (loaded as Font assets):

Bevy Scenes:

There are unofficial plugins available for adding support for even more file formats.

GLTF Asset Labels

Asset path labels to refer to GLTF sub-assets.

The following asset labels are supported ({} is the numerical index):

• Scene{}: GLTF Scene as Bevy Scene
• Node{}: GLTF Node as GltfNode
• Mesh{}: GLTF Mesh as GltfMesh
• Mesh{}/Primitive{}: GLTF Primitive as Bevy Mesh
• Mesh{}/Primitive{}/MorphTargets: Morph target animation data for a GLTF Primitive
• Texture{}: GLTF Texture as Bevy Image
• Material{}: GLTF Material as Bevy StandardMaterial
• DefaultMaterial: as above, if the GLTF file contains a default material with no index
• Animation{}: GLTF Animation as Bevy AnimationClip
• Skin{}: GLTF mesh skin as Bevy SkinnedMeshInverseBindposes

Shader Imports

TODO

wgpu Backends

wgpu (and hence Bevy) supports the following backends:

On GLES3 and WebGL2, some renderer features are unsupported and performance is worse.

WebGPU is experimental and few browsers support it.

Schedules

Internally, Bevy has these built-in schedules:

• Main: runs every frame update cycle, to perform general app logic
• ExtractSchedule: runs after Main, to copy data from the Main World into the Render World
• Render: runs after ExtractSchedule, to perform all rendering/graphics, in parallel with the next Main run

The Main schedule simply runs a sequence of other schedules:

On the first run (first frame update of the app):

• PreStartup
• Startup
• PostStartup

On every run (controlled via the MainScheduleOrder resource):

• First: any initialization that must be done at the start of every frame
• PreUpdate: for engine-internal systems intended to run before user logic
• StateTransition: perform any pending state transitions
• RunFixedUpdateLoop: runs the FixedUpdate schedule as many times as needed
• Update: for all user logic (your systems) that should run every frame
• PostUpdate: for engine-internal systems intended to run after user logic
• Last: any final cleanup that must be done at the end of every frame

FixedUpdate is for all user logic (your systems) that should run at a fixed timestep.

StateTransition runs the OnEnter(...)/OnTransition(...)/OnExit(...) schedules for your states, when you want to change state.

The Render schedule is organized using sets (RenderSet):

• ExtractCommands: apply deferred buffers from systems that ran in ExtractSchedule
• Prepare/PrepareFlush: set up data on the GPU (buffers, textures, etc.)
• Queue/QueueFlush: generate the render jobs to be run (usually phase items)
• PhaseSort/PhaseSortFlush: sort and batch phase items for efficient rendering
• Render/RenderFlush: execute the render graph to actually trigger the GPU to do work
• Cleanup/CleanupFlush: clear any data from the render World that should not persist to the next frame

The *Flush variants are just to apply any deferred buffers after every step, if needed.

Run Conditions

TODO

Plugins

TODO

Bundles

Bevy's built-in bundle types, for spawning different common kinds of entities.

(List in API Docs)

Any tuples of up to 15 Component types are valid bundles.

General:

• SpatialBundle: Contains the required transform and visibility components that must be included on all entities that need rendering or hierarchy
• TransformBundle: Contains only the transform types, subset of SpatialBundle
• VisibilityBundle: Contains only the visibility types, subset of SpatialBundle

Scenes:

• SceneBundle: Used for spawning scenes
• DynamicSceneBundle: Used for spawning dynamic scenes

Audio:

• AudioBundle: Play audio from an AudioSource asset
• SpatialAudioBundle: Play positional audio from an AudioSource asset
• AudioSourceBundle: Play audio from a custom data source/stream
• SpatialAudioSourceBundle: Play positional audio from a custom data source/stream

Bevy 3D:

• Camera3dBundle: 3D camera, can use perspective (default) or orthographic projection
• TemporalAntiAliasBundle: Add this to a 3D camera to enable TAA
• ScreenSpaceAmbientOcclusionBundle: Add this to a 3D camera to enable SSAO
• MaterialMeshBundle: 3D Object/Primitive: a Mesh and a custom Material to draw it with
• PbrBundle: MaterialMeshBundle with the default Physically-Based Material (StandardMaterial)
• DirectionalLightBundle: 3D directional light (like the sun)
• PointLightBundle: 3D point light (like a lamp or candle)
• SpotLightBundle: 3D spot light (like a projector or flashlight)

Bevy 2D:

• Camera2dBundle: 2D camera, uses orthographic projection + other special configuration for 2D
• SpriteBundle: 2D sprite (Image asset type)
• SpriteSheetBundle: 2D sprite (TextureAtlas asset type)
• MaterialMesh2dBundle: 2D shape, with custom Mesh and Material (similar to 3D objects)
• Text2dBundle: Text to be drawn in the 2D world (not the UI)

Bevy UI:

• NodeBundle: Empty node element (like HTML <div>)
• ButtonBundle: Button element
• ImageBundle: Image element (Image asset type)
• AtlasImageBundle: Image element (TextureAtlas asset type)
• TextBundle: Text element

Resources

(more info about working with resources)

Configuration Resources

These resources allow you to change the settings for how various parts of Bevy work.

These may be inserted at the start, but should also be fine to change at runtime (from a system):

• ClearColor: Global renderer background color to clear the window at the start of each frame
• GlobalVolume: The overall volume for playing audio
• AmbientLight: Global renderer "fake lighting", so that shadows don't look too dark / black
• Msaa: Global renderer setting for Multi-Sample Anti-Aliasing (some platforms might only support the values 1 and 4)
• UiScale: Global scale value to make all UIs bigger/smaller
• GizmoConfig: Controls how gizmos are rendered
• WireframeConfig: Global toggle to make everything be rendered as wireframe
• GamepadSettings: Gamepad input device settings, like joystick deadzones and button sensitivities
• WinitSettings: Settings for the OS Windowing backend, including update loop / power-management settings
• TimeUpdateStrategy: Used to control how the Time is updated
• Schedules: Stores all schedules, letting you register additional functionality at runtime
• MainScheduleOrder: The sequence of schedules that will run every frame update

Settings that are not modifiable at runtime are not represented using resources. Instead, they are configured via the respective plugins.

Engine Resources

These resources provide access to different features of the game engine at runtime.

Access them from your systems, if you need their state, or to control the respective parts of Bevy. These resources are in the Main World. See here for the resources in the Render World.

• Time: Global time-related information (current frame delta time, time since startup, etc.)
• FixedTime: Tracks remaining time until the next fixed update
• AssetServer: Control the asset system: Load assets, check load status, etc.
• Assets<T>: Contains the actual data of the loaded assets of a given type
• State<T>: The current value of a states type
• NextState<T>: Used to queue a transition to another state
• Gamepads: Tracks the IDs for all currently-detected (connected) gamepad devices
• SceneSpawner: Direct control over spawning Scenes into the main app World
• FrameCount: The total number of frames
• ScreenshotManager: Used to request a screenshot of a window to be taken/saved
• AppTypeRegistry: Access to the Reflection Type Registry
• AsyncComputeTaskPool: Task pool for running background CPU tasks
• ComputeTaskPool: Task pool where the main app schedule (all the systems) runs
• IoTaskPool: Task pool where background i/o tasks run (like asset loading)
• WinitWindows (non-send): Raw state of the winit backend for each window
• NonSendMarker: Dummy resource to ensure a system always runs on the main thread

Render World Resources

These resources are present in the Render World. They can be accessed from rendering systems (that run during render stages).

• MainWorld: (extract schedule only!) access data from the Main World
• RenderGraph: The Bevy Render Graph
• PipelineCache: Bevy's manager of render pipelines. Used to store render pipelines used by the app, to avoid recreating them more than once.
• TextureCache: Bevy's manager of temporary textures. Useful when you need textures to use internally during rendering.
• DrawFunctions<P>: Stores draw functions for a given phase item type
• RenderAssets<T>: Contains handles to the GPU representations of currently loaded asset data
• DefaultImageSampler: The default sampler for Image asset textures
• FallbackImage: Dummy 1x1 pixel white texture. Useful for shaders that normally need a texture, when you don't have one available.

There are many other resources in the Render World, which are not mentioned here, either because they are internal to Bevy's rendering algorithms, or because they are just extracted copies of the equivalent resources in the Main World.

Low-Level wgpu Resources

Using these resources, you can have direct access to the wgpu APIs for controlling the GPU. These are available in both the Main World and the Render World.

• RenderDevice: The GPU device, used for creating hardware resources for rendering/compute
• RenderQueue: The GPU queue for submitting work to the hardware
• RenderAdapter: Handle to the physical GPU hardware
• RenderAdapterInfo: Information about the GPU hardware that Bevy is running on

Input Handling Resources

These resources represent the current state of different input devices. Read them from your systems to handle user input.

• Input<KeyCode>: Keyboard key state, as a binary Input value
• Input<MouseButton>: Mouse button state, as a binary Input value
• Input<GamepadButton>: Gamepad buttons, as a binary Input value
• Axis<GamepadAxis>: Analog Axis gamepad inputs (joysticks and triggers)
• Axis<GamepadButton>: Gamepad buttons, represented as an analog Axis value
• Touches: The state of all fingers currently touching the touchscreen
• Gamepads: Registry of all the connected Gamepad IDs

Events

(more info about working with events)

Input Events

These events fire on activity with input devices. Read them to [handle user input][cb::input].

• MouseButtonInput: Changes in the state of mouse buttons
• MouseWheel: Scrolling by a number of pixels or lines (MouseScrollUnit)
• MouseMotion: Relative movement of the mouse (pixels from previous frame), regardless of the OS pointer/cursor
• CursorMoved: New position of the OS mouse pointer/cursor
• KeyboardInput: Changes in the state of keyboard keys (keypresses, not text)
• ReceivedCharacter: Unicode text input from the OS (correct handling of the user's language and layout)
• Ime: Unicode text input from IME (support for advanced text input in different scripts)
• TouchInput: Change in the state of a finger touching the touchscreen
• GamepadEvent: Changes in the state of a gamepad or any of its buttons or axes
• GamepadRumbleRequest: Send these events to control gamepad rumble
• TouchpadMagnify: Pinch-to-zoom gesture on laptop touchpad (macOS)
• TouchpadRotate: Two-finger rotate gesture on laptop touchpad (macOS)

Engine Events

Events related to various internal things happening during the normal runtime of a Bevy app.

• AssetEvent<T>: Sent by Bevy when asset data has been added/modified/removed; can be used to detect changes to assets
• HierarchyEvent: Sent by Bevy when entity parents/children change
• AppExit: Tell Bevy to shut down

System and Control Events

Events from the OS / windowing system, or to control Bevy.

• RequestRedraw: In an app that does not refresh continuously, request one more update before going to sleep
• FileDragAndDrop: The user drag-and-dropped a file into our app
• CursorEntered: OS mouse pointer/cursor entered one of our windows
• CursorLeft: OS mouse pointer/cursor exited one of our windows
• WindowCloseRequested: OS wants to close one of our windows
• WindowCreated: New application window opened
• WindowClosed: Bevy window closed
• WindowDestroyed: OS window freed/dropped after window close
• WindowFocused: One of our windows is now focused
• WindowMoved: OS/user moved one of our windows
• WindowResized: OS/user resized one of our windows
• WindowScaleFactorChanged: One of our windows has changed its DPI scaling factor
• WindowBackendScaleFactorChanged: OS reports change in DPI scaling factor for a window

Components

The complete list of individual component types is too specific to be useful to list here.

See: (List in API Docs)