Struct bevy::asset::Assets

pub struct Assets<A>
where
    A: Asset,
{ /* private fields */ }

Stores Asset values identified by their AssetId.

Assets identified by AssetId::Index will be stored in a “dense” vec-like storage. This is more efficient, but it means that the assets can only be identified at runtime. This is the default behavior.

Assets identified by AssetId::Uuid will be stored in a hashmap. This is less efficient, but it means that the assets can be referenced at compile time.

This tracks (and queues) AssetEvent events whenever changes to the collection occur.

Implementations

impl<A> Assets<A>

where A: Asset,

pub fn get_handle_provider(&self) -> AssetHandleProvider

Retrieves an AssetHandleProvider capable of reserving new Handle values for assets that will be stored in this collection.

pub fn reserve_handle(&self) -> Handle<A>

Reserves a new Handle for an asset that will be stored in this collection.

pub fn insert(&mut self, id: impl Into<AssetId<A>>, asset: A)

Inserts the given asset, identified by the given id. If an asset already exists for id, it will be replaced.

Examples found in repository

examples/2d/mesh2d_manual.rs (lines 289-292)

    fn build(&self, app: &mut App) {
        // Load our custom shader
        let mut shaders = app.world.resource_mut::<Assets<Shader>>();
        shaders.insert(
            COLORED_MESH2D_SHADER_HANDLE,
            Shader::from_wgsl(COLORED_MESH2D_SHADER, file!()),
        );

        // Register our custom draw function, and add our render systems
        app.get_sub_app_mut(RenderApp)
            .unwrap()
            .add_render_command::<Transparent2d, DrawColoredMesh2d>()
            .init_resource::<SpecializedRenderPipelines<ColoredMesh2dPipeline>>()
            .add_systems(
                ExtractSchedule,
                extract_colored_mesh2d.after(extract_mesh2d),
            )
            .add_systems(Render, queue_colored_mesh2d.in_set(RenderSet::QueueMeshes));
    }

examples/3d/tonemapping.rs (line 347)

fn resize_image(
    image_mesh: Query<(&Handle<StandardMaterial>, &Handle<Mesh>), With<HDRViewer>>,
    materials: Res<Assets<StandardMaterial>>,
    mut meshes: ResMut<Assets<Mesh>>,
    images: Res<Assets<Image>>,
    mut image_events: EventReader<AssetEvent<Image>>,
) {
    for event in image_events.read() {
        let (AssetEvent::Added { id } | AssetEvent::Modified { id }) = event else {
            continue;
        };

        for (mat_h, mesh_h) in &image_mesh {
            let Some(mat) = materials.get(mat_h) else {
                continue;
            };

            let Some(ref base_color_texture) = mat.base_color_texture else {
                continue;
            };

            if *id != base_color_texture.id() {
                continue;
            };

            let Some(image_changed) = images.get(*id) else {
                continue;
            };

            let size = image_changed.size_f32().normalize_or_zero() * 1.4;
            // Resize Mesh
            let quad = Mesh::from(Rectangle::from_size(size));
            meshes.insert(mesh_h, quad);
        }
    }
}

pub fn get_or_insert_with( &mut self, id: impl Into<AssetId<A>>, insert_fn: impl FnOnce() -> A ) -> &mut A

Retrieves an Asset stored for the given id if it exists. If it does not exist, it will be inserted using insert_fn.

pub fn contains(&self, id: impl Into<AssetId<A>>) -> bool

Returns true if the id exists in this collection. Otherwise it returns false.

pub fn add(&mut self, asset: impl Into<A>) -> Handle<A>

Adds the given asset and allocates a new strong Handle for it.

Examples found in repository

examples/audio/decodable.rs (lines 97-99)

fn setup(mut assets: ResMut<Assets<SineAudio>>, mut commands: Commands) {
    // add a `SineAudio` to the asset server so that it can be played
    let audio_handle = assets.add(SineAudio {
        frequency: 440., //this is the frequency of A4
    });
    commands.spawn(AudioSourceBundle {
        source: audio_handle,
        ..default()
    });
}

examples/async_tasks/async_compute.rs (line 38)

fn add_assets(
    mut commands: Commands,
    mut meshes: ResMut<Assets<Mesh>>,
    mut materials: ResMut<Assets<StandardMaterial>>,
) {
    let box_mesh_handle = meshes.add(Cuboid::new(0.25, 0.25, 0.25));
    commands.insert_resource(BoxMeshHandle(box_mesh_handle));

    let box_material_handle = materials.add(Color::rgb(1.0, 0.2, 0.3));
    commands.insert_resource(BoxMaterialHandle(box_material_handle));
}

examples/2d/mesh2d.rs (line 21)

fn setup(
    mut commands: Commands,
    mut meshes: ResMut<Assets<Mesh>>,
    mut materials: ResMut<Assets<ColorMaterial>>,
) {
    commands.spawn(Camera2dBundle::default());
    commands.spawn(MaterialMesh2dBundle {
        mesh: meshes.add(Rectangle::default()).into(),
        transform: Transform::default().with_scale(Vec3::splat(128.)),
        material: materials.add(Color::PURPLE),
        ..default()
    });
}

examples/2d/pixel_grid_snap.rs (line 86)

fn setup_mesh(
    mut commands: Commands,
    mut meshes: ResMut<Assets<Mesh>>,
    mut materials: ResMut<Assets<ColorMaterial>>,
) {
    commands.spawn((
        MaterialMesh2dBundle {
            mesh: meshes.add(Capsule2d::default()).into(),
            transform: Transform::from_xyz(40., 0., 2.).with_scale(Vec3::splat(32.)),
            material: materials.add(Color::BLACK),
            ..default()
        },
        Rotate,
        PIXEL_PERFECT_LAYERS,
    ));
}

fn setup_camera(mut commands: Commands, mut images: ResMut<Assets<Image>>) {
    let canvas_size = Extent3d {
        width: RES_WIDTH,
        height: RES_HEIGHT,
        ..default()
    };

    // this Image serves as a canvas representing the low-resolution game screen
    let mut canvas = Image {
        texture_descriptor: TextureDescriptor {
            label: None,
            size: canvas_size,
            dimension: TextureDimension::D2,
            format: TextureFormat::Bgra8UnormSrgb,
            mip_level_count: 1,
            sample_count: 1,
            usage: TextureUsages::TEXTURE_BINDING
                | TextureUsages::COPY_DST
                | TextureUsages::RENDER_ATTACHMENT,
            view_formats: &[],
        },
        ..default()
    };

    // fill image.data with zeroes
    canvas.resize(canvas_size);

    let image_handle = images.add(canvas);

    // this camera renders whatever is on `PIXEL_PERFECT_LAYERS` to the canvas
    commands.spawn((
        Camera2dBundle {
            camera: Camera {
                // render before the "main pass" camera
                order: -1,
                target: RenderTarget::Image(image_handle.clone()),
                ..default()
            },
            ..default()
        },
        InGameCamera,
        PIXEL_PERFECT_LAYERS,
    ));

    // spawn the canvas
    commands.spawn((
        SpriteBundle {
            texture: image_handle,
            ..default()
        },
        Canvas,
        HIGH_RES_LAYERS,
    ));

    // the "outer" camera renders whatever is on `HIGH_RES_LAYERS` to the screen.
    // here, the canvas and one of the sample sprites will be rendered by this camera
    commands.spawn((Camera2dBundle::default(), OuterCamera, HIGH_RES_LAYERS));
}

examples/audio/pitch.rs (line 34)

fn play_pitch(
    mut pitch_assets: ResMut<Assets<Pitch>>,
    frequency: Res<PitchFrequency>,
    mut events: EventReader<PlayPitch>,
    mut commands: Commands,
) {
    for _ in events.read() {
        info!("playing pitch with frequency: {}", frequency.0);
        commands.spawn(PitchBundle {
            source: pitch_assets.add(Pitch::new(frequency.0, Duration::new(1, 0))),
            settings: PlaybackSettings::DESPAWN,
        });
        info!("number of pitch assets: {}", pitch_assets.len());
    }
}

examples/shader/animate_shader.rs (line 24)

fn setup(
    mut commands: Commands,
    mut meshes: ResMut<Assets<Mesh>>,
    mut materials: ResMut<Assets<CustomMaterial>>,
) {
    // cube
    commands.spawn(MaterialMeshBundle {
        mesh: meshes.add(Cuboid::default()),
        transform: Transform::from_xyz(0.0, 0.5, 0.0),
        material: materials.add(CustomMaterial {}),
        ..default()
    });

    // camera
    commands.spawn(Camera3dBundle {
        transform: Transform::from_xyz(-2.0, 2.5, 5.0).looking_at(Vec3::ZERO, Vec3::Y),
        ..default()
    });
}

Additional examples can be found in:

• examples/2d/custom_gltf_vertex_attribute.rs
• examples/shader/shader_material_2d.rs
• examples/3d/reflection_probes.rs
• examples/shader/fallback_image.rs
• examples/shader/shader_material.rs
• examples/3d/3d_viewport_to_world.rs
• examples/shader/texture_binding_array.rs
• examples/shader/compute_shader_game_of_life.rs
• examples/shader/custom_vertex_attribute.rs
• examples/transforms/3d_rotation.rs
• examples/transforms/scale.rs
• examples/transforms/translation.rs
• examples/shader/shader_defs.rs
• tests/window/minimising.rs
• tests/window/resizing.rs
• examples/2d/sprite_sheet.rs
• examples/ui/ui_material.rs
• examples/3d/animated_material.rs
• examples/3d/3d_scene.rs
• examples/shader/shader_material_screenspace_texture.rs
• examples/shader/array_texture.rs
• examples/shader/post_processing.rs
• examples/3d/parenting.rs
• examples/3d/lines.rs
• examples/2d/2d_shapes.rs
• examples/3d/two_passes.rs
• examples/shader/shader_instancing.rs
• examples/window/screenshot.rs
• examples/math/render_primitives.rs
• examples/3d/deterministic.rs
• examples/3d/atmospheric_fog.rs
• examples/3d/irradiance_volumes.rs
• examples/animation/cubic_curve.rs
• examples/2d/mesh2d_vertex_color_texture.rs
• examples/shader/extended_material.rs
• examples/3d/vertex_colors.rs
• examples/3d/orthographic.rs
• examples/3d/generate_custom_mesh.rs
• examples/3d/3d_shapes.rs
• examples/transforms/transform.rs
• examples/ui/ui_texture_atlas.rs
• examples/3d/spherical_area_lights.rs
• examples/animation/animated_fox.rs
• examples/stress_tests/many_animated_sprites.rs
• examples/3d/3d_gizmos.rs
• examples/3d/wireframe.rs
• examples/2d/bloom_2d.rs
• examples/window/low_power.rs
• examples/audio/spatial_audio_2d.rs
• examples/3d/fog.rs
• examples/audio/spatial_audio_3d.rs
• examples/3d/texture.rs
• examples/stress_tests/many_lights.rs
• examples/3d/ssao.rs
• examples/3d/shadow_caster_receiver.rs
• examples/3d/bloom_3d.rs
• examples/3d/transparency_3d.rs
• examples/ecs/iter_combinations.rs
• examples/3d/anti_aliasing.rs
• examples/2d/mesh2d_manual.rs
• examples/ui/render_ui_to_texture.rs
• examples/stress_tests/bevymark.rs
• examples/asset/asset_loading.rs
• examples/3d/tonemapping.rs
• examples/3d/pbr.rs
• examples/3d/spotlight.rs
• examples/3d/render_to_texture.rs
• examples/stress_tests/many_foxes.rs
• examples/shader/shader_prepass.rs
• examples/stress_tests/many_cubes.rs
• examples/animation/custom_skinned_mesh.rs
• examples/games/breakout.rs
• examples/2d/texture_atlas.rs
• examples/3d/parallax_mapping.rs
• examples/3d/split_screen.rs
• examples/3d/shadow_biases.rs
• examples/animation/animated_transform.rs
• examples/3d/deferred_rendering.rs
• examples/3d/blend_modes.rs
• examples/3d/lighting.rs
• examples/3d/transmission.rs

pub fn get(&self, id: impl Into<AssetId<A>>) -> Option<&A>

Retrieves a reference to the Asset with the given id, if its exists. Note that this supports anything that implements Into<AssetId<A>>, which includes Handle and AssetId.

Examples found in repository

examples/animation/morph_targets.rs (line 86)

fn name_morphs(
    mut has_printed: Local<bool>,
    morph_data: Res<MorphData>,
    meshes: Res<Assets<Mesh>>,
) {
    if *has_printed {
        return;
    }

    let Some(mesh) = meshes.get(&morph_data.mesh) else {
        return;
    };
    let Some(names) = mesh.morph_target_names() else {
        return;
    };
    for name in names {
        println!("  {name}");
    }
    *has_printed = true;
}

examples/stress_tests/many_animated_sprites.rs (line 129)

fn animate_sprite(
    time: Res<Time>,
    texture_atlases: Res<Assets<TextureAtlasLayout>>,
    mut query: Query<(&mut AnimationTimer, &mut TextureAtlas)>,
) {
    for (mut timer, mut sheet) in query.iter_mut() {
        timer.tick(time.delta());
        if timer.just_finished() {
            let texture_atlas = texture_atlases.get(&sheet.layout).unwrap();
            sheet.index = (sheet.index + 1) % texture_atlas.textures.len();
        }
    }
}

examples/asset/custom_asset.rs (line 132)

fn print_on_load(
    mut state: ResMut<State>,
    custom_assets: Res<Assets<CustomAsset>>,
    blob_assets: Res<Assets<Blob>>,
) {
    let custom_asset = custom_assets.get(&state.handle);
    let other_custom_asset = custom_assets.get(&state.other_handle);
    let blob = blob_assets.get(&state.blob);

    // Can't print results if the assets aren't ready
    if state.printed {
        return;
    }

    if custom_asset.is_none() {
        info!("Custom Asset Not Ready");
        return;
    }

    if other_custom_asset.is_none() {
        info!("Other Custom Asset Not Ready");
        return;
    }

    if blob.is_none() {
        info!("Blob Not Ready");
        return;
    }

    info!("Custom asset loaded: {:?}", custom_asset.unwrap());
    info!("Custom asset loaded: {:?}", other_custom_asset.unwrap());
    info!("Blob Size: {:?} Bytes", blob.unwrap().bytes.len());

    // Once printed, we won't print again
    state.printed = true;
}

examples/3d/tonemapping.rs (line 328)

fn resize_image(
    image_mesh: Query<(&Handle<StandardMaterial>, &Handle<Mesh>), With<HDRViewer>>,
    materials: Res<Assets<StandardMaterial>>,
    mut meshes: ResMut<Assets<Mesh>>,
    images: Res<Assets<Image>>,
    mut image_events: EventReader<AssetEvent<Image>>,
) {
    for event in image_events.read() {
        let (AssetEvent::Added { id } | AssetEvent::Modified { id }) = event else {
            continue;
        };

        for (mat_h, mesh_h) in &image_mesh {
            let Some(mat) = materials.get(mat_h) else {
                continue;
            };

            let Some(ref base_color_texture) = mat.base_color_texture else {
                continue;
            };

            if *id != base_color_texture.id() {
                continue;
            };

            let Some(image_changed) = images.get(*id) else {
                continue;
            };

            let size = image_changed.size_f32().normalize_or_zero() * 1.4;
            // Resize Mesh
            let quad = Mesh::from(Rectangle::from_size(size));
            meshes.insert(mesh_h, quad);
        }
    }
}

examples/3d/irradiance_volumes.rs (line 576)

fn create_cubes(
    image_assets: Res<Assets<Image>>,
    mut commands: Commands,
    irradiance_volumes: Query<(&IrradianceVolume, &GlobalTransform)>,
    voxel_cube_parents: Query<Entity, With<VoxelCubeParent>>,
    voxel_cubes: Query<Entity, With<VoxelCube>>,
    example_assets: Res<ExampleAssets>,
    mut voxel_visualization_material_assets: ResMut<Assets<VoxelVisualizationMaterial>>,
) {
    // If voxel cubes have already been spawned, don't do anything.
    if !voxel_cubes.is_empty() {
        return;
    }

    let Some(voxel_cube_parent) = voxel_cube_parents.iter().next() else {
        return;
    };

    for (irradiance_volume, global_transform) in irradiance_volumes.iter() {
        let Some(image) = image_assets.get(&irradiance_volume.voxels) else {
            continue;
        };

        let resolution = image.texture_descriptor.size;

        let voxel_cube_material = voxel_visualization_material_assets.add(ExtendedMaterial {
            base: StandardMaterial::from(Color::RED),
            extension: VoxelVisualizationExtension {
                irradiance_volume_info: VoxelVisualizationIrradianceVolumeInfo {
                    transform: VOXEL_TRANSFORM.inverse(),
                    inverse_transform: VOXEL_TRANSFORM,
                    resolution: uvec3(
                        resolution.width,
                        resolution.height,
                        resolution.depth_or_array_layers,
                    ),
                    intensity: IRRADIANCE_VOLUME_INTENSITY,
                },
            },
        });

        let scale = vec3(
            1.0 / resolution.width as f32,
            1.0 / resolution.height as f32,
            1.0 / resolution.depth_or_array_layers as f32,
        );

        // Spawn a cube for each voxel.
        for z in 0..resolution.depth_or_array_layers {
            for y in 0..resolution.height {
                for x in 0..resolution.width {
                    let uvw = (uvec3(x, y, z).as_vec3() + 0.5) * scale - 0.5;
                    let pos = global_transform.transform_point(uvw);
                    let voxel_cube = commands
                        .spawn(MaterialMeshBundle {
                            mesh: example_assets.voxel_cube.clone(),
                            material: voxel_cube_material.clone(),
                            transform: Transform::from_scale(Vec3::splat(VOXEL_CUBE_SCALE))
                                .with_translation(pos),
                            ..default()
                        })
                        .insert(VoxelCube)
                        .insert(NotShadowCaster)
                        .id();

                    commands.entity(voxel_cube_parent).add_child(voxel_cube);
                }
            }
        }
    }
}

examples/asset/asset_loading.rs (line 30)

fn setup(
    mut commands: Commands,
    asset_server: Res<AssetServer>,
    meshes: Res<Assets<Mesh>>,
    mut materials: ResMut<Assets<StandardMaterial>>,
) {
    // By default AssetServer will load assets from inside the "assets" folder.
    // For example, the next line will load "ROOT/assets/models/cube/cube.gltf#Mesh0/Primitive0",
    // where "ROOT" is the directory of the Application.
    //
    // This can be overridden by setting the "CARGO_MANIFEST_DIR" environment variable (see
    // https://doc.rust-lang.org/cargo/reference/environment-variables.html)
    // to another directory. When the Application is run through Cargo, "CARGO_MANIFEST_DIR" is
    // automatically set to your crate (workspace) root directory.
    let cube_handle = asset_server.load("models/cube/cube.gltf#Mesh0/Primitive0");
    let sphere_handle = asset_server.load("models/sphere/sphere.gltf#Mesh0/Primitive0");

    // All assets end up in their Assets<T> collection once they are done loading:
    if let Some(sphere) = meshes.get(&sphere_handle) {
        // You might notice that this doesn't run! This is because assets load in parallel without
        // blocking. When an asset has loaded, it will appear in relevant Assets<T>
        // collection.
        info!("{:?}", sphere.primitive_topology());
    } else {
        info!("sphere hasn't loaded yet");
    }

    // You can load all assets in a folder like this. They will be loaded in parallel without
    // blocking. The LoadedFolder asset holds handles to each asset in the folder. These are all
    // dependencies of the LoadedFolder asset, meaning you can wait for the LoadedFolder asset to
    // fire AssetEvent::LoadedWithDependencies if you want to wait for all assets in the folder
    // to load.
    // If you want to keep the assets in the folder alive, make sure you store the returned handle
    // somewhere.
    let _loaded_folder: Handle<LoadedFolder> = asset_server.load_folder("models/torus");

    // If you want a handle to a specific asset in a loaded folder, the easiest way to get one is to call load.
    // It will _not_ be loaded a second time.
    // The LoadedFolder asset will ultimately also hold handles to the assets, but waiting for it to load
    // and finding the right handle is more work!
    let torus_handle = asset_server.load("models/torus/torus.gltf#Mesh0/Primitive0");

    // You can also add assets directly to their Assets<T> storage:
    let material_handle = materials.add(StandardMaterial {
        base_color: Color::rgb(0.8, 0.7, 0.6),
        ..default()
    });

    // torus
    commands.spawn(PbrBundle {
        mesh: torus_handle,
        material: material_handle.clone(),
        transform: Transform::from_xyz(-3.0, 0.0, 0.0),
        ..default()
    });
    // cube
    commands.spawn(PbrBundle {
        mesh: cube_handle,
        material: material_handle.clone(),
        transform: Transform::from_xyz(0.0, 0.0, 0.0),
        ..default()
    });
    // sphere
    commands.spawn(PbrBundle {
        mesh: sphere_handle,
        material: material_handle,
        transform: Transform::from_xyz(3.0, 0.0, 0.0),
        ..default()
    });
    // light
    commands.spawn(PointLightBundle {
        transform: Transform::from_xyz(4.0, 5.0, 4.0),
        ..default()
    });
    // camera
    commands.spawn(Camera3dBundle {
        transform: Transform::from_xyz(0.0, 3.0, 10.0).looking_at(Vec3::ZERO, Vec3::Y),
        ..default()
    });
}

Additional examples can be found in:

• examples/2d/texture_atlas.rs

pub fn get_mut(&mut self, id: impl Into<AssetId<A>>) -> Option<&mut A>

Retrieves a mutable reference to the Asset with the given id, if its exists. Note that this supports anything that implements Into<AssetId<A>>, which includes Handle and AssetId.

Examples found in repository

examples/3d/deferred_rendering.rs (line 298)

fn update_normal(
    mut already_ran: Local<bool>,
    mut images: ResMut<Assets<Image>>,
    normal: Res<Normal>,
) {
    if *already_ran {
        return;
    }
    if let Some(normal) = normal.0.as_ref() {
        if let Some(image) = images.get_mut(normal) {
            image.texture_descriptor.format = TextureFormat::Rgba8Unorm;
            *already_ran = true;
        }
    }
}

examples/3d/parallax_mapping.rs (line 368)

fn update_normal(
    mut already_ran: Local<bool>,
    mut images: ResMut<Assets<Image>>,
    normal: Res<Normal>,
) {
    if *already_ran {
        return;
    }
    if let Some(normal) = normal.0.as_ref() {
        if let Some(image) = images.get_mut(normal) {
            image.texture_descriptor.format = TextureFormat::Rgba8Unorm;
            *already_ran = true;
        }
    }
}

examples/3d/animated_material.rs (line 51)

fn animate_materials(
    material_handles: Query<&Handle<StandardMaterial>>,
    time: Res<Time>,
    mut materials: ResMut<Assets<StandardMaterial>>,
) {
    for (i, material_handle) in material_handles.iter().enumerate() {
        if let Some(material) = materials.get_mut(material_handle) {
            let color = Color::hsl(
                ((i as f32 * 2.345 + time.elapsed_seconds_wrapped()) * 100.0) % 360.0,
                1.0,
                0.5,
            );
            material.base_color = color;
        }
    }
}

examples/3d/tonemapping.rs (line 304)

fn drag_drop_image(
    image_mat: Query<&Handle<StandardMaterial>, With<HDRViewer>>,
    text: Query<Entity, (With<Text>, With<SceneNumber>)>,
    mut materials: ResMut<Assets<StandardMaterial>>,
    mut drop_events: EventReader<FileDragAndDrop>,
    asset_server: Res<AssetServer>,
    mut commands: Commands,
) {
    let Some(new_image) = drop_events.read().find_map(|e| match e {
        FileDragAndDrop::DroppedFile { path_buf, .. } => {
            Some(asset_server.load(path_buf.to_string_lossy().to_string()))
        }
        _ => None,
    }) else {
        return;
    };

    for mat_h in &image_mat {
        if let Some(mat) = materials.get_mut(mat_h) {
            mat.base_color_texture = Some(new_image.clone());

            // Despawn the image viewer instructions
            if let Ok(text_entity) = text.get_single() {
                commands.entity(text_entity).despawn();
            }
        }
    }
}

examples/shader/shader_prepass.rs (line 248)

fn toggle_prepass_view(
    mut prepass_view: Local<u32>,
    keycode: Res<ButtonInput<KeyCode>>,
    material_handle: Query<&Handle<PrepassOutputMaterial>>,
    mut materials: ResMut<Assets<PrepassOutputMaterial>>,
    mut text: Query<&mut Text>,
) {
    if keycode.just_pressed(KeyCode::Space) {
        *prepass_view = (*prepass_view + 1) % 4;

        let label = match *prepass_view {
            0 => "transparent",
            1 => "depth",
            2 => "normals",
            3 => "motion vectors",
            _ => unreachable!(),
        };
        let mut text = text.single_mut();
        text.sections[0].value = format!("Prepass Output: {label}\n");
        for section in &mut text.sections {
            section.style.color = Color::WHITE;
        }

        let handle = material_handle.single();
        let mat = materials.get_mut(handle).unwrap();
        mat.settings.show_depth = (*prepass_view == 1) as u32;
        mat.settings.show_normals = (*prepass_view == 2) as u32;
        mat.settings.show_motion_vectors = (*prepass_view == 3) as u32;
    }
}

examples/2d/texture_atlas.rs (line 229)

fn create_texture_atlas(
    folder: &LoadedFolder,
    padding: Option<UVec2>,
    sampling: Option<ImageSampler>,
    textures: &mut ResMut<Assets<Image>>,
) -> (TextureAtlasLayout, Handle<Image>) {
    // Build a texture atlas using the individual sprites
    let mut texture_atlas_builder =
        TextureAtlasBuilder::default().padding(padding.unwrap_or_default());
    for handle in folder.handles.iter() {
        let id = handle.id().typed_unchecked::<Image>();
        let Some(texture) = textures.get(id) else {
            warn!(
                "{:?} did not resolve to an `Image` asset.",
                handle.path().unwrap()
            );
            continue;
        };

        texture_atlas_builder.add_texture(Some(id), texture);
    }

    let (texture_atlas_layout, texture) = texture_atlas_builder.finish().unwrap();
    let texture = textures.add(texture);

    // Update the sampling settings of the texture atlas
    let image = textures.get_mut(&texture).unwrap();
    image.sampler = sampling.unwrap_or_default();

    (texture_atlas_layout, texture)
}

Additional examples can be found in:

• examples/3d/skybox.rs
• examples/3d/generate_custom_mesh.rs
• examples/shader/array_texture.rs
• examples/3d/lightmaps.rs
• examples/3d/blend_modes.rs
• examples/3d/transmission.rs

pub fn remove(&mut self, id: impl Into<AssetId<A>>) -> Option<A>

Removes (and returns) the Asset with the given id, if its exists. Note that this supports anything that implements Into<AssetId<A>>, which includes Handle and AssetId.

Examples found in repository

examples/asset/asset_decompression.rs (line 127)

fn decompress<A: Asset>(
    mut commands: Commands,
    asset_server: Res<AssetServer>,
    mut compressed_assets: ResMut<Assets<GzAsset>>,
    query: Query<(Entity, &Compressed<A>)>,
) {
    for (entity, Compressed { compressed, .. }) in query.iter() {
        let Some(GzAsset { uncompressed }) = compressed_assets.remove(compressed) else {
            continue;
        };

        let uncompressed = uncompressed.take::<A>().unwrap();

        commands
            .entity(entity)
            .remove::<Compressed<A>>()
            .insert(asset_server.add(uncompressed));
    }
}

pub fn remove_untracked(&mut self, id: impl Into<AssetId<A>>) -> Option<A>

Removes (and returns) the Asset with the given id, if its exists. This skips emitting AssetEvent::Removed. Note that this supports anything that implements Into<AssetId<A>>, which includes Handle and AssetId.

pub fn is_empty(&self) -> bool

Returns true if there are no assets in this collection.

pub fn len(&self) -> usize

Returns the number of assets currently stored in the collection.

Examples found in repository

examples/audio/pitch.rs (line 37)

fn play_pitch(
    mut pitch_assets: ResMut<Assets<Pitch>>,
    frequency: Res<PitchFrequency>,
    mut events: EventReader<PlayPitch>,
    mut commands: Commands,
) {
    for _ in events.read() {
        info!("playing pitch with frequency: {}", frequency.0);
        commands.spawn(PitchBundle {
            source: pitch_assets.add(Pitch::new(frequency.0, Duration::new(1, 0))),
            settings: PlaybackSettings::DESPAWN,
        });
        info!("number of pitch assets: {}", pitch_assets.len());
    }
}

pub fn ids(&self) -> impl Iterator<Item = AssetId<A>>

Returns an iterator over the AssetId of every Asset stored in this collection.

pub fn iter(&self) -> impl Iterator<Item = (AssetId<A>, &A)>

Returns an iterator over the AssetId and Asset ref of every asset in this collection.

pub fn iter_mut(&mut self) -> AssetsMutIterator<'_, A>

Returns an iterator over the AssetId and mutable Asset ref of every asset in this collection.

Examples found in repository

examples/3d/transparency_3d.rs (line 103)

pub fn fade_transparency(time: Res<Time>, mut materials: ResMut<Assets<StandardMaterial>>) {
    let alpha = (time.elapsed_seconds().sin() / 2.0) + 0.5;
    for (_, material) in materials.iter_mut() {
        material.base_color.set_a(alpha);
    }
}

examples/ui/ui_material.rs (line 17)

fn update(time: Res<Time>, mut ui_materials: ResMut<Assets<CustomUiMaterial>>) {
    for (_, material) in ui_materials.iter_mut() {
        // rainbow color effect
        let new_color = Color::hsl((time.elapsed_seconds() * 60.0) % 360.0, 1., 0.5);
        material.color = new_color.rgba_to_vec4();
    }
}

examples/3d/parallax_mapping.rs (line 100)

fn update_parallax_depth_scale(
    input: Res<ButtonInput<KeyCode>>,
    mut materials: ResMut<Assets<StandardMaterial>>,
    mut target_depth: Local<TargetDepth>,
    mut depth_update: Local<bool>,
    mut text: Query<&mut Text>,
) {
    if input.just_pressed(KeyCode::Digit1) {
        target_depth.0 -= DEPTH_UPDATE_STEP;
        target_depth.0 = target_depth.0.max(0.0);
        *depth_update = true;
    }
    if input.just_pressed(KeyCode::Digit2) {
        target_depth.0 += DEPTH_UPDATE_STEP;
        target_depth.0 = target_depth.0.min(MAX_DEPTH);
        *depth_update = true;
    }
    if *depth_update {
        let mut text = text.single_mut();
        for (_, mat) in materials.iter_mut() {
            let current_depth = mat.parallax_depth_scale;
            let new_depth = current_depth.lerp(target_depth.0, DEPTH_CHANGE_RATE);
            mat.parallax_depth_scale = new_depth;
            text.sections[0].value = format!("Parallax depth scale: {new_depth:.5}\n");
            if (new_depth - current_depth).abs() <= 0.000000001 {
                *depth_update = false;
            }
        }
    }
}

fn switch_method(
    input: Res<ButtonInput<KeyCode>>,
    mut materials: ResMut<Assets<StandardMaterial>>,
    mut text: Query<&mut Text>,
    mut current: Local<CurrentMethod>,
) {
    if input.just_pressed(KeyCode::Space) {
        current.next_method();
    } else {
        return;
    }
    let mut text = text.single_mut();
    text.sections[2].value = format!("Method: {}\n", *current);

    for (_, mat) in materials.iter_mut() {
        mat.parallax_mapping_method = current.0;
    }
}

fn update_parallax_layers(
    input: Res<ButtonInput<KeyCode>>,
    mut materials: ResMut<Assets<StandardMaterial>>,
    mut target_layers: Local<TargetLayers>,
    mut text: Query<&mut Text>,
) {
    if input.just_pressed(KeyCode::Digit3) {
        target_layers.0 -= 1.0;
        target_layers.0 = target_layers.0.max(0.0);
    } else if input.just_pressed(KeyCode::Digit4) {
        target_layers.0 += 1.0;
    } else {
        return;
    }
    let layer_count = target_layers.0.exp2();
    let mut text = text.single_mut();
    text.sections[1].value = format!("Layers: {layer_count:.0}\n");

    for (_, mat) in materials.iter_mut() {
        mat.max_parallax_layer_count = layer_count;
    }
}

examples/3d/deferred_rendering.rs (line 354)

fn switch_mode(
    mut text: Query<&mut Text>,
    mut commands: Commands,
    keys: Res<ButtonInput<KeyCode>>,
    mut default_opaque_renderer_method: ResMut<DefaultOpaqueRendererMethod>,
    mut materials: ResMut<Assets<StandardMaterial>>,
    cameras: Query<Entity, With<Camera>>,
    mut pause: ResMut<Pause>,
    mut hide_ui: Local<bool>,
    mut mode: Local<DefaultRenderMode>,
) {
    let mut text = text.single_mut();
    let text = &mut text.sections[0].value;

    text.clear();

    if keys.just_pressed(KeyCode::Space) {
        pause.0 = !pause.0;
    }

    if keys.just_pressed(KeyCode::Digit1) {
        *mode = DefaultRenderMode::Deferred;
        default_opaque_renderer_method.set_to_deferred();
        println!("DefaultOpaqueRendererMethod: Deferred");
        for _ in materials.iter_mut() {}
        for camera in &cameras {
            commands.entity(camera).remove::<NormalPrepass>();
            commands.entity(camera).insert(DepthPrepass);
            commands.entity(camera).insert(MotionVectorPrepass);
            commands.entity(camera).insert(DeferredPrepass);
        }
    }
    if keys.just_pressed(KeyCode::Digit2) {
        *mode = DefaultRenderMode::Forward;
        default_opaque_renderer_method.set_to_forward();
        println!("DefaultOpaqueRendererMethod: Forward");
        for _ in materials.iter_mut() {}
        for camera in &cameras {
            commands.entity(camera).remove::<NormalPrepass>();
            commands.entity(camera).remove::<DepthPrepass>();
            commands.entity(camera).remove::<MotionVectorPrepass>();
            commands.entity(camera).remove::<DeferredPrepass>();
        }
    }
    if keys.just_pressed(KeyCode::Digit3) {
        *mode = DefaultRenderMode::ForwardPrepass;
        default_opaque_renderer_method.set_to_forward();
        println!("DefaultOpaqueRendererMethod: Forward + Prepass");
        for _ in materials.iter_mut() {}
        for camera in &cameras {
            commands.entity(camera).insert(NormalPrepass);
            commands.entity(camera).insert(DepthPrepass);
            commands.entity(camera).insert(MotionVectorPrepass);
            commands.entity(camera).remove::<DeferredPrepass>();
        }
    }

    if keys.just_pressed(KeyCode::KeyH) {
        *hide_ui = !*hide_ui;
    }

    if !*hide_ui {
        text.push_str("(H) Hide UI\n");
        text.push_str("(Space) Play/Pause\n\n");
        text.push_str("Rendering Method:\n");

        text.push_str(&format!(
            "(1) {} Deferred\n",
            if let DefaultRenderMode::Deferred = *mode {
                ">"
            } else {
                ""
            }
        ));
        text.push_str(&format!(
            "(2) {} Forward\n",
            if let DefaultRenderMode::Forward = *mode {
                ">"
            } else {
                ""
            }
        ));
        text.push_str(&format!(
            "(3) {} Forward + Prepass\n",
            if let DefaultRenderMode::ForwardPrepass = *mode {
                ">"
            } else {
                ""
            }
        ));
    }
}

pub fn track_assets( assets: ResMut<'_, Assets<A>>, asset_server: Res<'_, AssetServer> )

A system that synchronizes the state of assets in this collection with the AssetServer. This manages Handle drop events.

pub fn asset_events( assets: ResMut<'_, Assets<A>>, events: EventWriter<'_, AssetEvent<A>> )

A system that applies accumulated asset change events to the Events resource.

Trait Implementations

impl<A> Default for Assets<A>

where A: Asset,

fn default() -> Assets<A>

Returns the “default value” for a type.

impl<A> Resource for Assets<A>

where A: Asset, Assets<A>: Send + Sync + 'static,