spherical_area_lights/
spherical_area_lights.rs

1//! Demonstrates how lighting is affected by different radius of point lights.
2
3use bevy::prelude::*;
4
5fn 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
16fn 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}
spherical_area_lights/spherical_area_lights.rs

spherical_area_lights/
spherical_area_lights.rs
