Bevy shaders and materials

When to use

Load this when a surface needs a material or a custom shader asset. 3D PBR defaults stay on bevy-3d-materials. Do not treat this as a Godot shader-language port.

ECS shape

• Features on the crate page: bevy_shader (shaders through asset handles) and bevy_material (material abstraction).
• PBR hook: StandardMaterial is named in feature blurbs (pbr_anisotropy_texture and neighbors) and in the DistanceFog summary on the pbr page.
• Extension: ExtendedMaterial is on the pbr page as a material that extends a base material with extra shaders and data. Check that page for type parameters before writing them.
• Systems: material extraction is engine-owned. Do not schedule a custom shader compiler.

Coming from Godot

Godot idea	Bevy idiom
Shader material	A material asset handle. Check the shader docs for the source language before writing it.
Spatial shader	Unverified. Do not copy Godot shader hints.
Full-screen pass	bevy_post_process is a feature. Check that feature's docs for effect types before writing them.

Scope

• Check the bevy::shader and bevy::material module pages before naming a Shader struct or a Material trait method.
• Check the shader docs for WGSL entry points, bind group layout, and pipeline specialization keys before writing them.

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 shader language or hint syntax. WHY: Bevy code stays idiomatic ECS and uses only documented Bevy APIs.

• No Godot types in Bevy code. WHY: Bevy code stays idiomatic ECS and uses only documented Bevy APIs.

• No invented APIs or unnamed third-party crates as the chosen solver. 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 - API reference and Cargo feature list.
• Assets - Official asset catalog. No third-party crate was selected.
• Examples - Example tree on the latest branch.
• ECS - Component, systems, Query, Startup, Update, and .chain().
• Plugins - Plugin, DefaultPlugins, MinimalPlugins, and add_plugins.
• bevy::pbr - ExtendedMaterial, DistanceFog mentions StandardMaterial.
• bevy::material - Material module reference.

Related Skills

Prerequisites

• bevy-master - Hub and schedules.
• bevy-ecs-composition - Components and systems.
• bevy-3d-materials - StandardMaterial surface fields.
• bevy-asset-scenes - Asset handles.

Complements

• bevy-3d-lighting - Lights are not shaders.
• godot-shaders-basics - Equivalent Godot skill.

Downstream / consumers

• None yet.

Master

• bevy-master - Bevy router.