shadow_caster_receiver/
shadow_caster_receiver.rs

1//! Demonstrates how to prevent meshes from casting/receiving shadows in a 3d scene.
2
3use std::f32::consts::PI;
4
5use bevy::{
6    color::palettes::basic::{BLUE, LIME, RED},
7    light::{CascadeShadowConfigBuilder, NotShadowCaster, NotShadowReceiver},
8    prelude::*,
9};
10
11fn main() {
12    println!(
13        "Controls:
14    C      - toggle shadow casters (i.e. casters become not, and not casters become casters)
15    R      - toggle shadow receivers (i.e. receivers become not, and not receivers become receivers)
16    L      - switch between directional and point lights"
17    );
18    App::new()
19        .add_plugins(DefaultPlugins)
20        .add_systems(Startup, setup)
21        .add_systems(Update, (toggle_light, toggle_shadows))
22        .run();
23}
24
25/// set up a 3D scene to test shadow biases and perspective projections
26fn setup(
27    mut commands: Commands,
28    mut meshes: ResMut<Assets<Mesh>>,
29    mut materials: ResMut<Assets<StandardMaterial>>,
30) {
31    let spawn_plane_depth = 500.0f32;
32    let spawn_height = 2.0;
33    let sphere_radius = 0.25;
34
35    let white_handle = materials.add(StandardMaterial {
36        base_color: Color::WHITE,
37        perceptual_roughness: 1.0,
38        ..default()
39    });
40    let sphere_handle = meshes.add(Sphere::new(sphere_radius));
41
42    // sphere - initially a caster
43    commands.spawn((
44        Mesh3d(sphere_handle.clone()),
45        MeshMaterial3d(materials.add(Color::from(RED))),
46        Transform::from_xyz(-1.0, spawn_height, 0.0),
47    ));
48
49    // sphere - initially not a caster
50    commands.spawn((
51        Mesh3d(sphere_handle),
52        MeshMaterial3d(materials.add(Color::from(BLUE))),
53        Transform::from_xyz(1.0, spawn_height, 0.0),
54        NotShadowCaster,
55    ));
56
57    // floating plane - initially not a shadow receiver and not a caster
58    commands.spawn((
59        Mesh3d(meshes.add(Plane3d::default().mesh().size(20.0, 20.0))),
60        MeshMaterial3d(materials.add(Color::from(LIME))),
61        Transform::from_xyz(0.0, 1.0, -10.0),
62        NotShadowCaster,
63        NotShadowReceiver,
64    ));
65
66    // lower ground plane - initially a shadow receiver
67    commands.spawn((
68        Mesh3d(meshes.add(Plane3d::default().mesh().size(20.0, 20.0))),
69        MeshMaterial3d(white_handle),
70    ));
71
72    println!("Using DirectionalLight");
73
74    commands.spawn((
75        PointLight {
76            intensity: 0.0,
77            range: spawn_plane_depth,
78            color: Color::WHITE,
79            shadows_enabled: true,
80            ..default()
81        },
82        Transform::from_xyz(5.0, 5.0, 0.0),
83    ));
84
85    commands.spawn((
86        DirectionalLight {
87            illuminance: light_consts::lux::OVERCAST_DAY,
88            shadows_enabled: true,
89            ..default()
90        },
91        Transform::from_rotation(Quat::from_euler(EulerRot::ZYX, 0.0, PI / 2., -PI / 4.)),
92        CascadeShadowConfigBuilder {
93            first_cascade_far_bound: 7.0,
94            maximum_distance: 25.0,
95            ..default()
96        }
97        .build(),
98    ));
99
100    // camera
101    commands.spawn((
102        Camera3d::default(),
103        Transform::from_xyz(-5.0, 5.0, 5.0).looking_at(Vec3::new(-1.0, 1.0, 0.0), Vec3::Y),
104    ));
105}
106
107fn toggle_light(
108    input: Res<ButtonInput<KeyCode>>,
109    mut point_lights: Query<&mut PointLight>,
110    mut directional_lights: Query<&mut DirectionalLight>,
111) {
112    if input.just_pressed(KeyCode::KeyL) {
113        for mut light in &mut point_lights {
114            light.intensity = if light.intensity == 0.0 {
115                println!("Using PointLight");
116                1_000_000.0 // Mini-sun point light
117            } else {
118                0.0
119            };
120        }
121        for mut light in &mut directional_lights {
122            light.illuminance = if light.illuminance == 0.0 {
123                println!("Using DirectionalLight");
124                light_consts::lux::OVERCAST_DAY
125            } else {
126                0.0
127            };
128        }
129    }
130}
131
132fn toggle_shadows(
133    mut commands: Commands,
134    input: Res<ButtonInput<KeyCode>>,
135    mut queries: ParamSet<(
136        Query<Entity, (With<Mesh3d>, With<NotShadowCaster>)>,
137        Query<Entity, (With<Mesh3d>, With<NotShadowReceiver>)>,
138        Query<Entity, (With<Mesh3d>, Without<NotShadowCaster>)>,
139        Query<Entity, (With<Mesh3d>, Without<NotShadowReceiver>)>,
140    )>,
141) {
142    if input.just_pressed(KeyCode::KeyC) {
143        println!("Toggling casters");
144        for entity in queries.p0().iter() {
145            commands.entity(entity).remove::<NotShadowCaster>();
146        }
147        for entity in queries.p2().iter() {
148            commands.entity(entity).insert(NotShadowCaster);
149        }
150    }
151    if input.just_pressed(KeyCode::KeyR) {
152        println!("Toggling receivers");
153        for entity in queries.p1().iter() {
154            commands.entity(entity).remove::<NotShadowReceiver>();
155        }
156        for entity in queries.p3().iter() {
157            commands.entity(entity).insert(NotShadowReceiver);
158        }
159    }
160}
shadow_caster_receiver/shadow_caster_receiver.rs

shadow_caster_receiver/
shadow_caster_receiver.rs
