5e2cfb2f19
# Objective Users should be able to render cameras to specific areas of a render target, which enables scenarios like split screen, minimaps, etc. Builds on the new Camera Driven Rendering added here: #4745 Fixes: #202 Alternative to #1389 and #3626 (which are incompatible with the new Camera Driven Rendering) ## Solution  Cameras can now configure an optional "viewport", which defines a rectangle within their render target to draw to. If a `Viewport` is defined, the camera's `CameraProjection`, `View`, and visibility calculations will use the viewport configuration instead of the full render target. ```rust // This camera will render to the first half of the primary window (on the left side). commands.spawn_bundle(Camera3dBundle { camera: Camera { viewport: Some(Viewport { physical_position: UVec2::new(0, 0), physical_size: UVec2::new(window.physical_width() / 2, window.physical_height()), depth: 0.0..1.0, }), ..default() }, ..default() }); ``` To account for this, the `Camera` component has received a few adjustments: * `Camera` now has some new getter functions: * `logical_viewport_size`, `physical_viewport_size`, `logical_target_size`, `physical_target_size`, `projection_matrix` * All computed camera values are now private and live on the `ComputedCameraValues` field (logical/physical width/height, the projection matrix). They are now exposed on `Camera` via getters/setters This wasn't _needed_ for viewports, but it was long overdue. --- ## Changelog ### Added * `Camera` components now have a `viewport` field, which can be set to draw to a portion of a render target instead of the full target. * `Camera` component has some new functions: `logical_viewport_size`, `physical_viewport_size`, `logical_target_size`, `physical_target_size`, and `projection_matrix` * Added a new split_screen example illustrating how to render two cameras to the same scene ## Migration Guide `Camera::projection_matrix` is no longer a public field. Use the new `Camera::projection_matrix()` method instead: ```rust // Bevy 0.7 let projection = camera.projection_matrix; // Bevy 0.8 let projection = camera.projection_matrix(); ```
109 lines
3.5 KiB
Rust
109 lines
3.5 KiB
Rust
//! Renders two cameras to the same window to accomplish "split screen".
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use bevy::{
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core_pipeline::clear_color::ClearColorConfig,
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prelude::*,
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render::camera::Viewport,
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window::{WindowId, WindowResized},
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};
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fn main() {
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App::new()
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.add_plugins(DefaultPlugins)
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.add_startup_system(setup)
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.add_system(set_camera_viewports)
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.run();
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}
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/// set up a simple 3D scene
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fn setup(
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mut commands: Commands,
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asset_server: Res<AssetServer>,
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mut meshes: ResMut<Assets<Mesh>>,
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mut materials: ResMut<Assets<StandardMaterial>>,
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) {
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// plane
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commands.spawn_bundle(PbrBundle {
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mesh: meshes.add(Mesh::from(shape::Plane { size: 100.0 })),
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material: materials.add(Color::rgb(0.3, 0.5, 0.3).into()),
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..default()
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});
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commands.spawn_scene(asset_server.load("models/animated/Fox.glb#Scene0"));
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// Light
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commands.spawn_bundle(DirectionalLightBundle {
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transform: Transform::from_rotation(Quat::from_euler(
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EulerRot::ZYX,
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0.0,
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1.0,
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-std::f32::consts::FRAC_PI_4,
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)),
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directional_light: DirectionalLight {
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shadows_enabled: true,
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..default()
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},
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..default()
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});
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// Left Camera
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commands
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.spawn_bundle(Camera3dBundle {
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transform: Transform::from_xyz(0.0, 200.0, -100.0).looking_at(Vec3::ZERO, Vec3::Y),
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..default()
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})
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.insert(LeftCamera);
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// Right Camera
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commands
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.spawn_bundle(Camera3dBundle {
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transform: Transform::from_xyz(100.0, 100., 150.0).looking_at(Vec3::ZERO, Vec3::Y),
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camera: Camera {
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// Renders the right camera after the left camera, which has a default priority of 0
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priority: 1,
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..default()
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},
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camera_3d: Camera3d {
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// dont clear on the second camera because the first camera already cleared the window
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clear_color: ClearColorConfig::None,
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},
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..default()
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})
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.insert(RightCamera);
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}
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#[derive(Component)]
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struct LeftCamera;
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#[derive(Component)]
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struct RightCamera;
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fn set_camera_viewports(
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windows: Res<Windows>,
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mut resize_events: EventReader<WindowResized>,
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mut left_camera: Query<&mut Camera, (With<LeftCamera>, Without<RightCamera>)>,
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mut right_camera: Query<&mut Camera, With<RightCamera>>,
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) {
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// We need to dynamically resize the camera's viewports whenever the window size changes
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// so then each camera always takes up half the screen.
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// A resize_event is sent when the window is first created, allowing us to reuse this system for initial setup.
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for resize_event in resize_events.iter() {
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if resize_event.id == WindowId::primary() {
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let window = windows.primary();
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let mut left_camera = left_camera.single_mut();
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left_camera.viewport = Some(Viewport {
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physical_position: UVec2::new(0, 0),
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physical_size: UVec2::new(window.physical_width() / 2, window.physical_height()),
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..default()
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});
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let mut right_camera = right_camera.single_mut();
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right_camera.viewport = Some(Viewport {
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physical_position: UVec2::new(window.physical_width() / 2, 0),
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physical_size: UVec2::new(window.physical_width() / 2, window.physical_height()),
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..default()
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});
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}
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}
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}
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