asset_loading/
asset_loading.rs

1//! This example illustrates various ways to load assets.
2
3use bevy::{asset::LoadedFolder, prelude::*};
4
5fn main() {
6    App::new()
7        .add_plugins(DefaultPlugins)
8        .add_systems(Startup, setup)
9        .run();
10}
11
12fn setup(
13    mut commands: Commands,
14    asset_server: Res<AssetServer>,
15    meshes: Res<Assets<Mesh>>,
16    mut materials: ResMut<Assets<StandardMaterial>>,
17) {
18    // By default AssetServer will load assets from inside the "assets" folder.
19    // For example, the next line will load GltfAssetLabel::Primitive{mesh:0,primitive:0}.from_asset("ROOT/assets/models/cube/cube.gltf"),
20    // where "ROOT" is the directory of the Application.
21    //
22    // This can be overridden by setting [`AssetPlugin.file_path`].
23    let cube_handle = asset_server.load(
24        GltfAssetLabel::Primitive {
25            mesh: 0,
26            primitive: 0,
27        }
28        .from_asset("models/cube/cube.gltf"),
29    );
30    let sphere_handle = asset_server.load(
31        GltfAssetLabel::Primitive {
32            mesh: 0,
33            primitive: 0,
34        }
35        .from_asset("models/sphere/sphere.gltf"),
36    );
37
38    // All assets end up in their Assets<T> collection once they are done loading:
39    if let Some(sphere) = meshes.get(&sphere_handle) {
40        // You might notice that this doesn't run! This is because assets load in parallel without
41        // blocking. When an asset has loaded, it will appear in relevant Assets<T>
42        // collection.
43        info!("{:?}", sphere.primitive_topology());
44    } else {
45        info!("sphere hasn't loaded yet");
46    }
47
48    // You can load all assets in a folder like this. They will be loaded in parallel without
49    // blocking. The LoadedFolder asset holds handles to each asset in the folder. These are all
50    // dependencies of the LoadedFolder asset, meaning you can wait for the LoadedFolder asset to
51    // fire AssetEvent::LoadedWithDependencies if you want to wait for all assets in the folder
52    // to load.
53    // If you want to keep the assets in the folder alive, make sure you store the returned handle
54    // somewhere.
55    let _loaded_folder: Handle<LoadedFolder> = asset_server.load_folder("models/torus");
56
57    // If you want a handle to a specific asset in a loaded folder, the easiest way to get one is to call load.
58    // It will _not_ be loaded a second time.
59    // The LoadedFolder asset will ultimately also hold handles to the assets, but waiting for it to load
60    // and finding the right handle is more work!
61    let torus_handle = asset_server.load(
62        GltfAssetLabel::Primitive {
63            mesh: 0,
64            primitive: 0,
65        }
66        .from_asset("models/torus/torus.gltf"),
67    );
68
69    // You can also add assets directly to their Assets<T> storage:
70    let material_handle = materials.add(StandardMaterial {
71        base_color: Color::srgb(0.8, 0.7, 0.6),
72        ..default()
73    });
74
75    // torus
76    commands.spawn((
77        Mesh3d(torus_handle),
78        MeshMaterial3d(material_handle.clone()),
79        Transform::from_xyz(-3.0, 0.0, 0.0),
80    ));
81    // cube
82    commands.spawn((
83        Mesh3d(cube_handle),
84        MeshMaterial3d(material_handle.clone()),
85        Transform::from_xyz(0.0, 0.0, 0.0),
86    ));
87    // sphere
88    commands.spawn((
89        Mesh3d(sphere_handle),
90        MeshMaterial3d(material_handle),
91        Transform::from_xyz(3.0, 0.0, 0.0),
92    ));
93    // light
94    commands.spawn((PointLight::default(), Transform::from_xyz(4.0, 5.0, 4.0)));
95    // camera
96    commands.spawn((
97        Camera3d::default(),
98        Transform::from_xyz(0.0, 3.0, 10.0).looking_at(Vec3::ZERO, Vec3::Y),
99    ));
100}
asset_loading/asset_loading.rs

asset_loading/
asset_loading.rs
