lightmaps/
lightmaps.rs

1//! Rendering a scene with baked lightmaps.
2
3use argh::FromArgs;
4use bevy::{
5    core_pipeline::prepass::{DeferredPrepass, DepthPrepass, MotionVectorPrepass},
6    pbr::{DefaultOpaqueRendererMethod, Lightmap},
7    prelude::*,
8};
9
10/// Demonstrates lightmaps
11#[derive(FromArgs, Resource)]
12struct Args {
13    /// enables deferred shading
14    #[argh(switch)]
15    deferred: bool,
16    /// enables bicubic filtering
17    #[argh(switch)]
18    bicubic: bool,
19}
20
21fn main() {
22    #[cfg(not(target_arch = "wasm32"))]
23    let args: Args = argh::from_env();
24    #[cfg(target_arch = "wasm32")]
25    let args: Args = Args::from_args(&[], &[]).unwrap();
26
27    let mut app = App::new();
28    app.add_plugins(DefaultPlugins)
29        .insert_resource(AmbientLight::NONE);
30
31    if args.deferred {
32        app.insert_resource(DefaultOpaqueRendererMethod::deferred());
33    }
34
35    app.insert_resource(args)
36        .add_systems(Startup, setup)
37        .add_systems(Update, add_lightmaps_to_meshes)
38        .run();
39}
40
41fn setup(mut commands: Commands, asset_server: Res<AssetServer>, args: Res<Args>) {
42    commands.spawn(SceneRoot(asset_server.load(
43        GltfAssetLabel::Scene(0).from_asset("models/CornellBox/CornellBox.glb"),
44    )));
45
46    let mut camera = commands.spawn((
47        Camera3d::default(),
48        Transform::from_xyz(-278.0, 273.0, 800.0),
49    ));
50
51    if args.deferred {
52        camera.insert((
53            DepthPrepass,
54            MotionVectorPrepass,
55            DeferredPrepass,
56            Msaa::Off,
57        ));
58    }
59}
60
61fn add_lightmaps_to_meshes(
62    mut commands: Commands,
63    asset_server: Res<AssetServer>,
64    mut materials: ResMut<Assets<StandardMaterial>>,
65    meshes: Query<
66        (Entity, &Name, &MeshMaterial3d<StandardMaterial>),
67        (With<Mesh3d>, Without<Lightmap>),
68    >,
69    args: Res<Args>,
70) {
71    let exposure = 250.0;
72    for (entity, name, material) in meshes.iter() {
73        if &**name == "large_box" {
74            materials.get_mut(material).unwrap().lightmap_exposure = exposure;
75            commands.entity(entity).insert(Lightmap {
76                image: asset_server.load("lightmaps/CornellBox-Large.zstd.ktx2"),
77                bicubic_sampling: args.bicubic,
78                ..default()
79            });
80            continue;
81        }
82
83        if &**name == "small_box" {
84            materials.get_mut(material).unwrap().lightmap_exposure = exposure;
85            commands.entity(entity).insert(Lightmap {
86                image: asset_server.load("lightmaps/CornellBox-Small.zstd.ktx2"),
87                bicubic_sampling: args.bicubic,
88                ..default()
89            });
90            continue;
91        }
92
93        if name.starts_with("cornell_box") {
94            materials.get_mut(material).unwrap().lightmap_exposure = exposure;
95            commands.entity(entity).insert(Lightmap {
96                image: asset_server.load("lightmaps/CornellBox-Box.zstd.ktx2"),
97                bicubic_sampling: args.bicubic,
98                ..default()
99            });
100            continue;
101        }
102    }
103}
lightmaps/lightmaps.rs

lightmaps/
lightmaps.rs
