Bevy 0.10-dev Directional Light Playground

main.rs

use bevy::{ecs::world::Ref, pbr::CascadeShadowConfig, prelude::*};
use std::f32::consts::PI;

#[derive(Component)]
struct LightRotation {
    x: f32,
    y: f32,
}
#[derive(Resource, Clone)]
struct ConfigParams {
    num_cascades: usize,
    nearest_bound: f32,
    shadow_maximum_distance: f32,
    overlap_proportion: f32,
    near_plane: f32,
}
impl Default for ConfigParams {
    fn default() -> Self {
        Self {
            num_cascades: 4,
            nearest_bound: 5.0,
            shadow_maximum_distance: 1000.0,
            overlap_proportion: 0.2,
            near_plane: 0.1,
        }
    }
}
impl std::fmt::Display for ConfigParams {
    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
        write!(f, "num_cascades: {}\nnearest_bound: {}\nshadow_maximum_distance: {}\noverlap_proportion: {}\nnear_plane: {}\n", self.num_cascades, self.nearest_bound, self.shadow_maximum_distance, self.overlap_proportion, self.near_plane)?;
        Ok(())
    }
}

fn main() {
    App::new()
        .add_plugins(DefaultPlugins)
        .init_resource::<ConfigParams>()
        .add_startup_system(setup)
        .add_startup_system(setup_ui)
        .add_system(movement)
        .add_system(rotation)
        .add_system(config)
        .add_system(ui)
        .run();
}

fn setup_ui(mut commands: Commands, asset_server: Res<AssetServer>) {
    commands.spawn(TextBundle::from_section(
        "",
        TextStyle {
            font: asset_server.load("fonts/FiraMono-Medium.ttf"),
            font_size: 14.0,
            color: Color::BLACK,
        },
    ));
}

fn setup(
    mut commands: Commands,
    mut meshes: ResMut<Assets<Mesh>>,
    mut materials: ResMut<Assets<StandardMaterial>>,
) {
    let extents = 2000.0;
    let num = 75;
    let spacing = extents / (num - 1) as f32;

    // plane
    commands.spawn(PbrBundle {
        mesh: meshes.add(Mesh::from(shape::Plane { size: 2100.0 })),
        material: materials.add(Color::rgb(0.3, 0.5, 0.3).into()),
        ..default()
    });

    // gnomon
    let unlit = materials.add(StandardMaterial {
        base_color: Color::rgb(0.8, 0.7, 0.6),
        unlit: true,
        ..default()
    });
    let gnomon = meshes.add(Mesh::from(shape::Cube { size: 1.0 }));
    for x in 0..num {
        for z in 0..num {
            commands.spawn(PbrBundle {
                mesh: gnomon.clone(),
                material: unlit.clone(),
                transform: Transform::from_xyz(
                    -extents / 2. + x as f32 * spacing,
                    0.5,
                    -extents / 2. + z as f32 * spacing,
                )
                .with_scale(Vec3::new(1., 20., 1.)),
                ..default()
            });
        }
    }

    commands.spawn((
        DirectionalLightBundle {
            directional_light: DirectionalLight {
                shadows_enabled: true,
                ..default()
            },
            ..default()
        },
        LightRotation {
            x: -PI / 4.,
            y: PI / 4.,
        },
    ));

    // camera
    commands.spawn(Camera3dBundle {
        transform: Transform::from_xyz(-200.0, 100.0, 200.0).looking_at(Vec3::ZERO, Vec3::Y),
        ..default()
    });
}

fn movement(
    input: Res<Input<KeyCode>>,
    time: Res<Time>,
    mut query: Query<&mut Transform, With<Camera3d>>,
) {
    for mut transform in &mut query {
        let mut direction = Vec3::ZERO;
        let mut speed = 20.;

        if input.pressed(KeyCode::Up) {
            direction.z += 1.0;
        }
        if input.pressed(KeyCode::Down) {
            direction.z -= 1.0;
        }
        if input.pressed(KeyCode::Left) {
            direction.x -= 1.0;
        }
        if input.pressed(KeyCode::Right) {
            direction.x += 1.0;
        }
        if input.pressed(KeyCode::O) {
            direction.y -= 1.0;
        }
        if input.pressed(KeyCode::L) {
            direction.y += 1.0;
        }
        if input.any_pressed([KeyCode::LShift, KeyCode::RShift]) {
            speed *= 10.;
        }

        if direction != Vec3::ZERO {
            let vel = direction.normalize() * speed;

            let dt = time.delta_seconds();
            let forward = transform.forward() * Vec3::new(1., 0., 1.);
            let right = transform.right();

            transform.translation +=
                vel.x * dt * right + vel.y * dt * Vec3::Y + vel.z * dt * forward;
        }
    }
}

fn rotation(
    input: Res<Input<KeyCode>>,
    time: Res<Time>,
    mut query: Query<(&mut Transform, &mut LightRotation)>,
) {
    for (mut transform, mut rotation) in &mut query {
        let mut direction = 0.;
        if input.pressed(KeyCode::Q) {
            direction -= 1.0;
        }
        if input.pressed(KeyCode::E) {
            direction += 1.0;
        }

        rotation.y += time.delta_seconds() * 1.0 * direction;

        let mut direction = 0.;
        if input.pressed(KeyCode::W) {
            direction -= 1.0;
        }
        if input.pressed(KeyCode::S) {
            direction += 1.0;
        }

        rotation.x += time.delta_seconds() * 1.0 * direction;

        transform.rotation = Quat::from_euler(EulerRot::YXZ, rotation.y, rotation.x, 0.);
    }
}

fn config(
    input: Res<Input<KeyCode>>,
    time: Res<Time>,
    mut params: ResMut<ConfigParams>,
    mut query: Query<&mut CascadeShadowConfig>,
    mut proj_query: Query<&mut Projection>,
) {
    for mut config in &mut query {
        let mut changed = false;

        if input.just_pressed(KeyCode::R) {
            params.num_cascades = (params.num_cascades - 1).max(1);
            changed = true;
        }
        if input.just_pressed(KeyCode::T) {
            params.num_cascades += 1;
            changed = true;
        }

        if input.pressed(KeyCode::F) {
            params.nearest_bound -= 25. * time.delta_seconds();
            params.nearest_bound = params.nearest_bound.max(0.001);
            changed = true;
        }
        if input.pressed(KeyCode::G) {
            params.nearest_bound += 25. * time.delta_seconds();
            changed = true;
        }

        if input.pressed(KeyCode::C) {
            params.shadow_maximum_distance -= 50. * time.delta_seconds();
            changed = true;
        }
        if input.pressed(KeyCode::V) {
            params.shadow_maximum_distance += 50. * time.delta_seconds();
            changed = true;
        }

        if input.pressed(KeyCode::Y) {
            params.overlap_proportion -= 0.05 * time.delta_seconds();
            changed = true;
        }
        if input.pressed(KeyCode::U) {
            params.overlap_proportion += 0.05 * time.delta_seconds();
            changed = true;
        }

        let mut camera_changed = false;
        if input.pressed(KeyCode::H) {
            params.near_plane -= 25. * time.delta_seconds();
            params.near_plane = params.near_plane.max(0.);
            camera_changed = true;
        }
        if input.pressed(KeyCode::J) {
            params.near_plane += 25. * time.delta_seconds();
            camera_changed = true;
        }

        if changed {
            *config = CascadeShadowConfig::new(
                params.num_cascades,
                params.nearest_bound,
                params.shadow_maximum_distance,
                params.overlap_proportion,
            );
        }
        if camera_changed {
            for mut proj in &mut proj_query {
                if let Projection::Perspective(perspective) = &mut *proj {
                    perspective.near = params.near_plane;
                }
            }
        }
    }
}

fn ui(
    mut text_query: Query<&mut Text>,
    params: Res<ConfigParams>,
    rotation_query: Query<Ref<LightRotation>>,
    config_query: Query<Ref<CascadeShadowConfig>>,
    camera_query: Query<Ref<Transform>, With<Camera>>,
) {
    let camera = camera_query.single();
    let rotation = rotation_query.single();
    let config = config_query.single();

    if !camera.is_changed()
        && !params.is_changed()
        && !rotation.is_changed()
        && !config.is_changed()
    {
        return;
    }

    for mut text in text_query.iter_mut() {
        text.sections[0].value = format!(
            concat!(
                "[r/t] num_cascades: {}\n",
                "[f/g] nearest_bound: {}\n",
                "[c/v] shadow_maximum_distance: {}\n",
                "[y/u] overlap_proportion: {}\n",
                "[h/j] near_plane: {}\n",
                "bounds: {:?}\n",
                "[←/→ ↑/↓ o/l] camera: {:?}\n",
                "[q/w w/s] shadow rotation: {}, {}"
            ),
            params.num_cascades,
            params.nearest_bound,
            params.shadow_maximum_distance,
            params.overlap_proportion,
            params.near_plane,
            config.bounds,
            camera.translation,
            rotation.x,
            rotation.y
        );
    }
}