Bevy spatial queries

When to use

Load this when a design needs line of sight, a volume overlap, a ground probe, or a mouse pick. Screen-to-2D-world mapping that does not hit a collider is a camera helper, not a physics query.

ECS shape

• Components would own query origin, direction, and a mask once a solver defines them. Check the solver docs before naming those types.
• Resources would own a physics world. None was opened.
• Systems would run the query after the solver step. Order that with .chain() on the ECS page. The clock is Fixed / FixedMain from bevy::time, which is not a query API.
• Camera-only pick: Camera::viewport_to_world_2d with GlobalTransform maps a viewport position to a 2D world position. That is not an intersection test. See bevy-camera-systems.

Coming from Godot

Godot idea	Bevy idiom
Ray or shape cast	Check bevy-physics-2d or bevy-physics-3d before naming a cast API.
Mouse position in 2D world	viewport_to_world_2d on a Camera (bevy-camera-systems). A collider hit belongs with the physics skills once you choose a solver.
Exclude the caster	Unverified. Do not copy Godot RID exclude lists
Field-of-view fan	Design data on components. Check the docs for a sensor API before writing one.

Scope

• The bevy 0.20.0 feature list has no physics-engine feature, so there is no ray, shape, point, or sweep query to cite.
• Third-party plugins may be added with add_plugins. Check a physics crate's own docs before naming a query API.
• Piercing casts, reflection from normals, and ground volumes are unverified.

Expert Knowledge Delta

Target: Bevy 0.20+.

Core ECS types: Component, Resource, Query, Commands, Startup, Update, Fixed / FixedMain (bevy::time), .chain(), Plugin, DefaultPlugins, MinimalPlugins. Messages and observers are an ownership slot. See bevy-events-messaging for their APIs. Systems run in parallel unless .chain() orders the ones that conflict.

Who owns state

Piece	Owner	Who may mutate	Schedule
Data on one entity	Component	One system via Query	Update or FixedMain
One value for the whole app	Resource	One system	Startup to insert, then the schedule that reads it
Spawn	Commands	The spawning system	Startup for the initial world; later schedules for runtime spawn
Order that must not race	.chain()	The chained systems only	Same schedule
Plugin boundary	Plugin	build registers systems and resources	Before the app runs

Borrow rule: two systems that both mutably query the same component must be ordered (.chain()) or split so only one writes. Unrelated systems stay parallel. That is the ECS page rule, not a guess at a system-set API.

Decision

If you need	Do this	Do not
Per-entity data	Component + Query	A Godot node script
App-wide config or clock	Resource	Copy the value onto every entity
Stable simulation step	FixedMain and the Fixed clock	Tie simulation to raw frame Update
Startup spawn	Commands in Startup	Spawn from a render system
Cross-system notice that is not shared state	Message or observer slot in bevy-events-messaging	A new event type invented in this file
An API outside the documented set	Check the official docs first	A made-up crate or API

Load references/ecs-ownership.md for the ownership table.

NEVER

• Do not pin /0.20.0/ in docs URLs. WHY: links stay on latest; the 0.20 target is stated once in prose.

• Do not mutably query the same component from two unordered systems. WHY: the schedule runs systems in parallel unless .chain() orders them.

• Do not invent a physics, navigation, networking, or XR crate here. WHY: this skill only names documented Bevy crates and modules.

• No Godot ray, shape-cast, or direct-space-state types. WHY: Bevy code stays idiomatic ECS and uses only documented Bevy APIs.

• No Avian, Rapier, or any other named physics crate as the chosen solver. WHY: Bevy code stays idiomatic ECS and uses only documented Bevy APIs.

• No invented intersect_ray or mask APIs. WHY: Bevy code stays idiomatic ECS and uses only documented Bevy APIs.

Reference

docs.rs links use the unversioned latest permalink. The library pin on bevy-master stays 0.20.0.

Official Documentation

• Migration guides - Unversioned hop index.
• bevy crate - Unversioned API index. No spatial-query module was opened.
• Assets - Official asset catalog. No query plugin was selected.
• Examples - Example tree on the latest branch.
• ECS - Systems, Query, and .chain().
• bevy::camera - viewport_to_world_2d is a camera map, not a collider query. Details live on bevy-camera-systems.
• Quick Start: plugins - Third-party add_plugins without a chosen crate.

Related Skills

Prerequisites

• bevy-master - ECS ownership.
• bevy-camera-systems - Viewport to 2D world, without a hit test.

Complements

• bevy-physics-2d - 2D physics and solver choice.
• bevy-physics-3d - 3D physics and solver choice.
• godot-raycasting-queries - Equivalent Godot skill.

Downstream / consumers

• bevy-ai-navigation - Sensors that need a cast.

Master

• bevy-master - Bevy router.