docs/bevy/examples/3d/spherical_area_lights.rs 1.9 K · 66 lines · raw · history

1 //! Demonstrates how lighting is affected by different radius of point lights.
2
3 use bevy::prelude::*;
4
5 fn main() {
6 App::new()
7 .insert_resource(GlobalAmbientLight {
8 brightness: 60.0,
9 ..default()
10 })
11 .add_plugins(DefaultPlugins)
12 .add_systems(Startup, setup)
13 .run();
14 }
15
16 fn setup(
17 mut commands: Commands,
18 mut meshes: ResMut<Assets<Mesh>>,
19 mut materials: ResMut<Assets<StandardMaterial>>,
20 ) {
21 // camera
22 commands.spawn((
23 Camera3d::default(),
24 Transform::from_xyz(0.2, 1.5, 2.5).looking_at(Vec3::ZERO, Vec3::Y),
25 ));
26
27 // plane
28 commands.spawn((
29 Mesh3d(meshes.add(Plane3d::default().mesh().size(100.0, 100.0))),
30 MeshMaterial3d(materials.add(StandardMaterial {
31 base_color: Color::srgb(0.2, 0.2, 0.2),
32 perceptual_roughness: 0.08,
33 ..default()
34 })),
35 ));
36
37 const COUNT: usize = 6;
38 let position_range = -2.0..2.0;
39 let radius_range = 0.0..0.4;
40 let pos_len = position_range.end - position_range.start;
41 let radius_len = radius_range.end - radius_range.start;
42 let mesh = meshes.add(Sphere::new(1.0).mesh().uv(120, 64));
43
44 for i in 0..COUNT {
45 let percent = i as f32 / COUNT as f32;
46 let radius = radius_range.start + percent * radius_len;
47
48 // sphere light
49 commands
50 .spawn((
51 Mesh3d(mesh.clone()),
52 MeshMaterial3d(materials.add(StandardMaterial {
53 base_color: Color::srgb(0.5, 0.5, 1.0),
54 unlit: true,
55 ..default()
56 })),
57 Transform::from_xyz(position_range.start + percent * pos_len, 0.3, 0.0)
58 .with_scale(Vec3::splat(radius)),
59 ))
60 .with_child(PointLight {
61 radius,
62 color: Color::srgb(0.2, 0.2, 1.0),
63 ..default()
64 });
65 }
66 }