bevy/examples/3d/motion_blur.rs
Joona Aalto 25bfa80e60
Migrate cameras to required components (#15641)
# Objective

Yet another PR for migrating stuff to required components. This time,
cameras!

## Solution

As per the [selected
proposal](https://hackmd.io/tsYID4CGRiWxzsgawzxG_g#Combined-Proposal-1-Selected),
deprecate `Camera2dBundle` and `Camera3dBundle` in favor of `Camera2d`
and `Camera3d`.

Adding a `Camera` without `Camera2d` or `Camera3d` now logs a warning,
as suggested by Cart [on
Discord](https://discord.com/channels/691052431525675048/1264881140007702558/1291506402832945273).
I would personally like cameras to work a bit differently and be split
into a few more components, to avoid some footguns and confusing
semantics, but that is more controversial, and shouldn't block this core
migration.

## Testing

I ran a few 2D and 3D examples, and tried cameras with and without
render graphs.

---

## Migration Guide

`Camera2dBundle` and `Camera3dBundle` have been deprecated in favor of
`Camera2d` and `Camera3d`. Inserting them will now also insert the other
components required by them automatically.
2024-10-05 01:59:52 +00:00

387 lines
13 KiB
Rust

//! Demonstrates how to enable per-object motion blur. This rendering feature can be configured per
//! camera using the [`MotionBlur`] component.z
use bevy::{core_pipeline::motion_blur::MotionBlur, math::ops, prelude::*};
fn main() {
let mut app = App::new();
// MSAA and Motion Blur together are not compatible on WebGL
#[cfg(all(feature = "webgl2", target_arch = "wasm32", not(feature = "webgpu")))]
app.insert_resource(Msaa::Off);
app.add_plugins(DefaultPlugins)
.add_systems(Startup, (setup_camera, setup_scene, setup_ui))
.add_systems(Update, (keyboard_inputs, move_cars, move_camera).chain())
.run();
}
fn setup_camera(mut commands: Commands) {
commands.spawn((
Camera3d::default(),
// Add the `MotionBlur` component to a camera to enable motion blur.
// Motion blur requires the depth and motion vector prepass, which this bundle adds.
// Configure the amount and quality of motion blur per-camera using this component.
MotionBlur {
shutter_angle: 1.0,
samples: 2,
#[cfg(all(feature = "webgl2", target_arch = "wasm32", not(feature = "webgpu")))]
_webgl2_padding: Default::default(),
},
));
}
// Everything past this point is used to build the example, but isn't required to use motion blur.
#[derive(Resource)]
enum CameraMode {
Track,
Chase,
}
#[derive(Component)]
struct Moves(f32);
#[derive(Component)]
struct CameraTracked;
#[derive(Component)]
struct Rotates;
fn setup_scene(
asset_server: Res<AssetServer>,
mut images: ResMut<Assets<Image>>,
mut commands: Commands,
mut meshes: ResMut<Assets<Mesh>>,
mut materials: ResMut<Assets<StandardMaterial>>,
) {
commands.insert_resource(AmbientLight {
color: Color::WHITE,
brightness: 300.0,
});
commands.insert_resource(CameraMode::Chase);
commands.spawn((
DirectionalLight {
illuminance: 3_000.0,
shadows_enabled: true,
..default()
},
Transform::default().looking_to(Vec3::new(-1.0, -0.7, -1.0), Vec3::X),
));
// Sky
commands.spawn((
Mesh3d(meshes.add(Sphere::default())),
MeshMaterial3d(materials.add(StandardMaterial {
unlit: true,
base_color: Color::linear_rgb(0.1, 0.6, 1.0),
..default()
})),
Transform::default().with_scale(Vec3::splat(-4000.0)),
));
// Ground
let mut plane: Mesh = Plane3d::default().into();
let uv_size = 4000.0;
let uvs = vec![[uv_size, 0.0], [0.0, 0.0], [0.0, uv_size], [uv_size; 2]];
plane.insert_attribute(Mesh::ATTRIBUTE_UV_0, uvs);
commands.spawn((
Mesh3d(meshes.add(plane)),
MeshMaterial3d(materials.add(StandardMaterial {
base_color: Color::WHITE,
perceptual_roughness: 1.0,
base_color_texture: Some(images.add(uv_debug_texture())),
..default()
})),
Transform::from_xyz(0.0, -0.65, 0.0).with_scale(Vec3::splat(80.)),
));
spawn_cars(&asset_server, &mut meshes, &mut materials, &mut commands);
spawn_trees(&mut meshes, &mut materials, &mut commands);
spawn_barriers(&mut meshes, &mut materials, &mut commands);
}
fn spawn_cars(
asset_server: &AssetServer,
meshes: &mut Assets<Mesh>,
materials: &mut Assets<StandardMaterial>,
commands: &mut Commands,
) {
const N_CARS: usize = 20;
let box_mesh = meshes.add(Cuboid::new(0.3, 0.15, 0.55));
let cylinder = meshes.add(Cylinder::default());
let logo = asset_server.load("branding/icon.png");
let wheel_matl = materials.add(StandardMaterial {
base_color: Color::WHITE,
base_color_texture: Some(logo.clone()),
..default()
});
let mut matl = |color| {
materials.add(StandardMaterial {
base_color: color,
..default()
})
};
let colors = [
matl(Color::linear_rgb(1.0, 0.0, 0.0)),
matl(Color::linear_rgb(1.0, 1.0, 0.0)),
matl(Color::BLACK),
matl(Color::linear_rgb(0.0, 0.0, 1.0)),
matl(Color::linear_rgb(0.0, 1.0, 0.0)),
matl(Color::linear_rgb(1.0, 0.0, 1.0)),
matl(Color::linear_rgb(0.5, 0.5, 0.0)),
matl(Color::linear_rgb(1.0, 0.5, 0.0)),
];
for i in 0..N_CARS {
let color = colors[i % colors.len()].clone();
commands
.spawn((
Mesh3d(box_mesh.clone()),
MeshMaterial3d(color.clone()),
Transform::from_scale(Vec3::splat(0.5)),
Moves(i as f32 * 2.0),
))
.insert_if(CameraTracked, || i == 0)
.with_children(|parent| {
parent.spawn((
Mesh3d(box_mesh.clone()),
MeshMaterial3d(color),
Transform::from_xyz(0.0, 0.08, 0.03).with_scale(Vec3::new(1.0, 1.0, 0.5)),
));
let mut spawn_wheel = |x: f32, z: f32| {
parent.spawn((
Mesh3d(cylinder.clone()),
MeshMaterial3d(wheel_matl.clone()),
Transform::from_xyz(0.14 * x, -0.045, 0.15 * z)
.with_scale(Vec3::new(0.15, 0.04, 0.15))
.with_rotation(Quat::from_rotation_z(std::f32::consts::FRAC_PI_2)),
Rotates,
));
};
spawn_wheel(1.0, 1.0);
spawn_wheel(1.0, -1.0);
spawn_wheel(-1.0, 1.0);
spawn_wheel(-1.0, -1.0);
});
}
}
fn spawn_barriers(
meshes: &mut Assets<Mesh>,
materials: &mut Assets<StandardMaterial>,
commands: &mut Commands,
) {
const N_CONES: usize = 100;
let capsule = meshes.add(Capsule3d::default());
let matl = materials.add(StandardMaterial {
base_color: Color::srgb_u8(255, 87, 51),
reflectance: 1.0,
..default()
});
let mut spawn_with_offset = |offset: f32| {
for i in 0..N_CONES {
let pos = race_track_pos(
offset,
(i as f32) / (N_CONES as f32) * std::f32::consts::PI * 2.0,
);
commands.spawn((
Mesh3d(capsule.clone()),
MeshMaterial3d(matl.clone()),
Transform::from_xyz(pos.x, -0.65, pos.y).with_scale(Vec3::splat(0.07)),
));
}
};
spawn_with_offset(0.04);
spawn_with_offset(-0.04);
}
fn spawn_trees(
meshes: &mut Assets<Mesh>,
materials: &mut Assets<StandardMaterial>,
commands: &mut Commands,
) {
const N_TREES: usize = 30;
let capsule = meshes.add(Capsule3d::default());
let sphere = meshes.add(Sphere::default());
let leaves = materials.add(Color::linear_rgb(0.0, 1.0, 0.0));
let trunk = materials.add(Color::linear_rgb(0.4, 0.2, 0.2));
let mut spawn_with_offset = |offset: f32| {
for i in 0..N_TREES {
let pos = race_track_pos(
offset,
(i as f32) / (N_TREES as f32) * std::f32::consts::PI * 2.0,
);
let [x, z] = pos.into();
commands.spawn((
Mesh3d(sphere.clone()),
MeshMaterial3d(leaves.clone()),
Transform::from_xyz(x, -0.3, z).with_scale(Vec3::splat(0.3)),
));
commands.spawn((
Mesh3d(capsule.clone()),
MeshMaterial3d(trunk.clone()),
Transform::from_xyz(x, -0.5, z).with_scale(Vec3::new(0.05, 0.3, 0.05)),
));
}
};
spawn_with_offset(0.07);
spawn_with_offset(-0.07);
}
fn setup_ui(mut commands: Commands) {
let style = TextStyle::default();
commands.spawn(
TextBundle::from_sections(vec![
TextSection::new(String::new(), style.clone()),
TextSection::new(String::new(), style.clone()),
TextSection::new("1/2: -/+ shutter angle (blur amount)\n", style.clone()),
TextSection::new("3/4: -/+ sample count (blur quality)\n", style.clone()),
TextSection::new("Spacebar: cycle camera\n", style.clone()),
])
.with_style(Style {
position_type: PositionType::Absolute,
top: Val::Px(12.0),
left: Val::Px(12.0),
..default()
}),
);
}
fn keyboard_inputs(
mut motion_blur: Query<&mut MotionBlur>,
presses: Res<ButtonInput<KeyCode>>,
mut text: Query<&mut Text>,
mut camera: ResMut<CameraMode>,
) {
let mut motion_blur = motion_blur.single_mut();
if presses.just_pressed(KeyCode::Digit1) {
motion_blur.shutter_angle -= 0.25;
} else if presses.just_pressed(KeyCode::Digit2) {
motion_blur.shutter_angle += 0.25;
} else if presses.just_pressed(KeyCode::Digit3) {
motion_blur.samples = motion_blur.samples.saturating_sub(1);
} else if presses.just_pressed(KeyCode::Digit4) {
motion_blur.samples += 1;
} else if presses.just_pressed(KeyCode::Space) {
*camera = match *camera {
CameraMode::Track => CameraMode::Chase,
CameraMode::Chase => CameraMode::Track,
};
}
motion_blur.shutter_angle = motion_blur.shutter_angle.clamp(0.0, 1.0);
motion_blur.samples = motion_blur.samples.clamp(0, 64);
let mut text = text.single_mut();
text.sections[0].value = format!("Shutter angle: {:.2}\n", motion_blur.shutter_angle);
text.sections[1].value = format!("Samples: {:.5}\n", motion_blur.samples);
}
/// Parametric function for a looping race track. `offset` will return the point offset
/// perpendicular to the track at the given point.
fn race_track_pos(offset: f32, t: f32) -> Vec2 {
let x_tweak = 2.0;
let y_tweak = 3.0;
let scale = 8.0;
let x0 = ops::sin(x_tweak * t);
let y0 = ops::cos(y_tweak * t);
let dx = x_tweak * ops::cos(x_tweak * t);
let dy = y_tweak * -ops::sin(y_tweak * t);
let dl = ops::hypot(dx, dy);
let x = x0 + offset * dy / dl;
let y = y0 - offset * dx / dl;
Vec2::new(x, y) * scale
}
fn move_cars(
time: Res<Time>,
mut movables: Query<(&mut Transform, &Moves, &Children)>,
mut spins: Query<&mut Transform, (Without<Moves>, With<Rotates>)>,
) {
for (mut transform, moves, children) in &mut movables {
let time = time.elapsed_seconds() * 0.25;
let t = time + 0.5 * moves.0;
let dx = ops::cos(t);
let dz = -ops::sin(3.0 * t);
let speed_variation = (dx * dx + dz * dz).sqrt() * 0.15;
let t = t + speed_variation;
let prev = transform.translation;
transform.translation.x = race_track_pos(0.0, t).x;
transform.translation.z = race_track_pos(0.0, t).y;
transform.translation.y = -0.59;
let delta = transform.translation - prev;
transform.look_to(delta, Vec3::Y);
for child in children.iter() {
let Ok(mut wheel) = spins.get_mut(*child) else {
continue;
};
let radius = wheel.scale.x;
let circumference = 2.0 * std::f32::consts::PI * radius;
let angle = delta.length() / circumference * std::f32::consts::PI * 2.0;
wheel.rotate_local_y(angle);
}
}
}
fn move_camera(
mut camera: Query<(&mut Transform, &mut Projection), Without<CameraTracked>>,
tracked: Query<&Transform, With<CameraTracked>>,
mode: Res<CameraMode>,
) {
let tracked = tracked.single();
let (mut transform, mut projection) = camera.single_mut();
match *mode {
CameraMode::Track => {
transform.look_at(tracked.translation, Vec3::Y);
transform.translation = Vec3::new(15.0, -0.5, 0.0);
if let Projection::Perspective(perspective) = &mut *projection {
perspective.fov = 0.05;
}
}
CameraMode::Chase => {
transform.translation =
tracked.translation + Vec3::new(0.0, 0.15, 0.0) + tracked.back() * 0.6;
transform.look_to(*tracked.forward(), Vec3::Y);
if let Projection::Perspective(perspective) = &mut *projection {
perspective.fov = 1.0;
}
}
}
}
fn uv_debug_texture() -> Image {
use bevy::render::{render_asset::RenderAssetUsages, render_resource::*, texture::*};
const TEXTURE_SIZE: usize = 7;
let mut palette = [
164, 164, 164, 255, 168, 168, 168, 255, 153, 153, 153, 255, 139, 139, 139, 255, 153, 153,
153, 255, 177, 177, 177, 255, 159, 159, 159, 255,
];
let mut texture_data = [0; TEXTURE_SIZE * TEXTURE_SIZE * 4];
for y in 0..TEXTURE_SIZE {
let offset = TEXTURE_SIZE * y * 4;
texture_data[offset..(offset + TEXTURE_SIZE * 4)].copy_from_slice(&palette);
palette.rotate_right(12);
}
let mut img = Image::new_fill(
Extent3d {
width: TEXTURE_SIZE as u32,
height: TEXTURE_SIZE as u32,
depth_or_array_layers: 1,
},
TextureDimension::D2,
&texture_data,
TextureFormat::Rgba8UnormSrgb,
RenderAssetUsages::RENDER_WORLD,
);
img.sampler = ImageSampler::Descriptor(ImageSamplerDescriptor {
address_mode_u: ImageAddressMode::Repeat,
address_mode_v: ImageAddressMode::MirrorRepeat,
mag_filter: ImageFilterMode::Nearest,
..ImageSamplerDescriptor::linear()
});
img
}