Bevy 3D materials

When to use

Load this when a mesh needs a PBR surface. Custom shader extension points are on bevy-shaders. Lighting is on bevy-3d-lighting.

ECS shape

• Type: StandardMaterial (feature blurbs and DistanceFog).
• Extension: ExtendedMaterial on the pbr page.
• Features that mention StandardMaterial textures: pbr_anisotropy_texture, pbr_multi_layer_material_textures, pbr_specular_textures, pbr_transmission_textures. Check the struct page for field names before writing them.
• Plugin: bevy_pbr adds PBR rendering. It is part of the 3d render collection.

Surface choice

Need	Bevy idiom
PBR surface	StandardMaterial on MeshMaterial3d, with base_color, metallic, and perceptual_roughness.
Extra shader data on that surface	ExtendedMaterial<StandardMaterial, E> where E: MaterialExtension.
Transparency	alpha_mode: AlphaMode::Mask for cutout, AlphaMode::Blend for glass.

Examples

[dependencies]
bevy = "0.20"

Spawn a mesh with a metal StandardMaterial. The mesh component is Mesh3d. The material component is MeshMaterial3d<StandardMaterial>.

fn spawn_metal(
    mut commands: Commands,
    mut meshes: ResMut<Assets<Mesh>>,
    mut materials: ResMut<Assets<StandardMaterial>>,
) {
    let mesh = meshes.add(Cuboid::new(1.0, 1.0, 1.0));
    let material = materials.add(StandardMaterial {
        base_color: Color::srgb(0.75, 0.15, 0.12),
        metallic: 1.0,
        perceptual_roughness: 0.25,
        reflectance: 0.5,
        ..default()
    });
    commands.spawn((Mesh3d(mesh), MeshMaterial3d(material), Transform::default()));
}

Cutout foliage discards fragments under the mask. Glass uses alpha blending and a translucent base color.

fn cutout_leaf(image: Handle<Image>) -> StandardMaterial {
    StandardMaterial {
        base_color_texture: Some(image),
        alpha_mode: AlphaMode::Mask(0.5),
        diffuse_transmission: 0.4,
        cull_mode: None,
        ..default()
    }
}

fn glass() -> StandardMaterial {
    StandardMaterial {
        base_color: Color::srgba(0.7, 0.85, 1.0, 0.25),
        alpha_mode: AlphaMode::Blend,
        metallic: 0.0,
        perceptual_roughness: 0.05,
        ..default()
    }
}

One shared asset stays the source of truth. A runtime tint clones the handle's material into a new asset so other meshes keep the original.

fn tint_one_mesh(
    mut materials: ResMut<Assets<StandardMaterial>>,
    mesh: Query<&MeshMaterial3d<StandardMaterial>>,
) {
    let Ok(handle) = mesh.single() else {
        return;
    };
    let Some(source) = materials.get(handle.id()) else {
        return;
    };
    let mut tinted = source.clone();
    tinted.base_color = Color::srgb(0.2, 0.45, 0.9);
    let _unique = materials.add(tinted);
}

ExtendedMaterial keeps every StandardMaterial field and adds extension data. Register the concrete material type before spawning it.

use bevy::pbr::{ExtendedMaterial, MaterialExtension};
use bevy::render::render_resource::AsBindGroup;

#[derive(Asset, AsBindGroup, TypePath, Clone, Default)]
struct Wear {
    #[uniform(100)]
    amount: f32,
}

impl MaterialExtension for Wear {}

fn register_wear(app: &mut App) {
    app.add_plugins(MaterialPlugin::<ExtendedMaterial<StandardMaterial, Wear>>::default());
}

fn spawn_worn(
    mut commands: Commands,
    mut meshes: ResMut<Assets<Mesh>>,
    mut materials: ResMut<Assets<ExtendedMaterial<StandardMaterial, Wear>>>,
) {
    let mesh = meshes.add(Cuboid::new(1.0, 1.0, 1.0));
    let material = materials.add(ExtendedMaterial {
        base: StandardMaterial {
            base_color: Color::srgb(0.4, 0.35, 0.3),
            perceptual_roughness: 0.8,
            ..default()
        },
        extension: Wear { amount: 0.6 },
    });
    commands.spawn((Mesh3d(mesh), MeshMaterial3d(material)));
}

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 plain struct stored outside the world
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 material fields this skill did not name. WHY: unnamed fields change between Bevy releases and the compiler is the check.

• 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

The library pin on bevy-master stays 0.20.0. Permalinks stay unversioned.

Official Documentation

• Assets - Official asset catalog. No third-party crate was selected.
• Examples - Example tree on the latest branch.
• 3D examples - Mesh, material, and lighting samples.
• ECS - Component, systems, Query, Startup, Update, and .chain().
• Plugins - Plugin, DefaultPlugins, MinimalPlugins, and add_plugins.

Related Skills

Prerequisites

• bevy-master - Hub and schedules.
• bevy-ecs-composition - Components and systems.
• bevy-shaders - Custom shaders and material extensions.
• bevy-3d-lighting - Lights that shade the material.

Complements

• None yet.

Downstream / consumers

• None yet.

Master

• bevy-master - Bevy router.