bevy/examples/3d/camera_sub_view.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

272 lines
8.9 KiB
Rust

//! Demonstrates different sub view effects.
//!
//! A sub view is essentially a smaller section of a larger viewport. Some use
//! cases include:
//! - Split one image across multiple cameras, for use in a multimonitor setups
//! - Magnify a section of the image, by rendering a small sub view in another
//! camera
//! - Rapidly change the sub view offset to get a screen shake effect
use bevy::{
prelude::*,
render::camera::{ScalingMode, SubCameraView, Viewport},
};
const PADDING: u32 = 10;
const SMALL_SIZE: u32 = 100;
const LARGE_SIZE: u32 = 450;
const WINDOW_HEIGHT: f32 = (LARGE_SIZE + PADDING * 3 + SMALL_SIZE) as f32;
const WINDOW_WIDTH: f32 = (LARGE_SIZE * 2 + PADDING * 3) as f32;
fn main() {
App::new()
.add_plugins(DefaultPlugins.set(WindowPlugin {
primary_window: Some(Window {
// Fix window size to avoid issues with viewports on resizing
resize_constraints: WindowResizeConstraints {
min_width: WINDOW_WIDTH,
min_height: WINDOW_HEIGHT,
max_width: WINDOW_WIDTH,
max_height: WINDOW_HEIGHT,
},
..default()
}),
..default()
}))
.add_systems(Startup, setup)
.add_systems(Update, move_camera_view)
.run();
}
#[derive(Debug, Component)]
struct MovingCameraMarker;
/// Set up a simple 3D scene
fn setup(
mut commands: Commands,
mut meshes: ResMut<Assets<Mesh>>,
mut materials: ResMut<Assets<StandardMaterial>>,
) {
let transform = Transform::from_xyz(-2.0, 2.5, 5.0).looking_at(Vec3::ZERO, Vec3::Y);
// Plane
commands.spawn((
Mesh3d(meshes.add(Plane3d::default().mesh().size(5.0, 5.0))),
MeshMaterial3d(materials.add(Color::srgb(0.3, 0.5, 0.3))),
));
// Cube
commands.spawn((
Mesh3d(meshes.add(Cuboid::default())),
MeshMaterial3d(materials.add(Color::srgb(0.8, 0.7, 0.6))),
Transform::from_xyz(0.0, 0.5, 0.0),
));
// Light
commands.spawn((
PointLight {
shadows_enabled: true,
..default()
},
Transform::from_xyz(4.0, 8.0, 4.0),
));
// Main perspective Camera
commands.spawn((
Camera3d::default(),
Camera {
viewport: Option::from(Viewport {
physical_size: UVec2::new(LARGE_SIZE, LARGE_SIZE),
physical_position: UVec2::new(PADDING, PADDING * 2 + SMALL_SIZE),
..default()
}),
..default()
},
transform,
));
// Perspective camera left half
commands.spawn((
Camera3d::default(),
Camera {
viewport: Option::from(Viewport {
physical_size: UVec2::new(SMALL_SIZE, SMALL_SIZE),
physical_position: UVec2::new(PADDING, PADDING),
..default()
}),
sub_camera_view: Some(SubCameraView {
// Set the sub view camera to the right half of the full image
//
// The values of `full_size` and `size` do not have to be the
// exact values of your physical viewport. The important part is
// the ratio between them.
full_size: UVec2::new(10, 10),
// The `offset` is also relative to the values in `full_size`
// and `size`
offset: Vec2::new(5.0, 0.0),
size: UVec2::new(5, 10),
}),
order: 1,
..default()
},
transform,
));
// Perspective camera moving
commands.spawn((
Camera3d::default(),
Camera {
viewport: Option::from(Viewport {
physical_size: UVec2::new(SMALL_SIZE, SMALL_SIZE),
physical_position: UVec2::new(PADDING * 2 + SMALL_SIZE, PADDING),
..default()
}),
sub_camera_view: Some(SubCameraView {
// Set the sub view camera to a fifth of the full view and
// move it in another system
full_size: UVec2::new(500, 500),
offset: Vec2::ZERO,
size: UVec2::new(100, 100),
}),
order: 2,
..default()
},
transform,
MovingCameraMarker,
));
// Perspective camera control
commands.spawn((
Camera3d::default(),
Camera {
viewport: Option::from(Viewport {
physical_size: UVec2::new(SMALL_SIZE, SMALL_SIZE),
physical_position: UVec2::new(PADDING * 3 + SMALL_SIZE * 2, PADDING),
..default()
}),
sub_camera_view: Some(SubCameraView {
// Set the sub view to the full image, to ensure that it matches
// the projection without sub view
full_size: UVec2::new(450, 450),
offset: Vec2::ZERO,
size: UVec2::new(450, 450),
}),
order: 3,
..default()
},
transform,
));
// Main orthographic camera
commands.spawn((
Camera3d::default(),
Projection::from(OrthographicProjection {
scaling_mode: ScalingMode::FixedVertical(6.0),
..OrthographicProjection::default_3d()
}),
Camera {
viewport: Option::from(Viewport {
physical_size: UVec2::new(LARGE_SIZE, LARGE_SIZE),
physical_position: UVec2::new(PADDING * 2 + LARGE_SIZE, PADDING * 2 + SMALL_SIZE),
..default()
}),
order: 4,
..default()
},
transform,
));
// Orthographic camera left half
commands.spawn((
Camera3d::default(),
Projection::from(OrthographicProjection {
scaling_mode: ScalingMode::FixedVertical(6.0),
..OrthographicProjection::default_3d()
}),
Camera {
viewport: Option::from(Viewport {
physical_size: UVec2::new(SMALL_SIZE, SMALL_SIZE),
physical_position: UVec2::new(PADDING * 5 + SMALL_SIZE * 4, PADDING),
..default()
}),
sub_camera_view: Some(SubCameraView {
// Set the sub view camera to the left half of the full image.
//
// The values of `full_size` and `size` do not have to be the
// exact values of your physical viewport. The important part is
// the ratio between them.
full_size: UVec2::new(2, 2),
offset: Vec2::ZERO,
size: UVec2::new(1, 2),
}),
order: 5,
..default()
},
transform,
));
// Orthographic camera moving
commands.spawn((
Camera3d::default(),
Projection::from(OrthographicProjection {
scaling_mode: ScalingMode::FixedVertical(6.0),
..OrthographicProjection::default_3d()
}),
Camera {
viewport: Option::from(Viewport {
physical_size: UVec2::new(SMALL_SIZE, SMALL_SIZE),
physical_position: UVec2::new(PADDING * 6 + SMALL_SIZE * 5, PADDING),
..default()
}),
sub_camera_view: Some(SubCameraView {
// Set the sub view camera to a fifth of the full view and
// move it in another system
full_size: UVec2::new(500, 500),
offset: Vec2::ZERO,
size: UVec2::new(100, 100),
}),
order: 6,
..default()
},
transform,
MovingCameraMarker,
));
// Orthographic camera control
commands.spawn((
Camera3d::default(),
Projection::from(OrthographicProjection {
scaling_mode: ScalingMode::FixedVertical(6.0),
..OrthographicProjection::default_3d()
}),
Camera {
viewport: Option::from(Viewport {
physical_size: UVec2::new(SMALL_SIZE, SMALL_SIZE),
physical_position: UVec2::new(PADDING * 7 + SMALL_SIZE * 6, PADDING),
..default()
}),
sub_camera_view: Some(SubCameraView {
// Set the sub view to the full image, to ensure that it matches
// the projection without sub view
full_size: UVec2::new(450, 450),
offset: Vec2::ZERO,
size: UVec2::new(450, 450),
}),
order: 7,
..default()
},
transform,
));
}
fn move_camera_view(
mut movable_camera_query: Query<&mut Camera, With<MovingCameraMarker>>,
time: Res<Time>,
) {
for mut camera in movable_camera_query.iter_mut() {
if let Some(sub_view) = &mut camera.sub_camera_view {
sub_view.offset.x = (time.elapsed_seconds() * 150.) % 450.0 - 50.0;
sub_view.offset.y = sub_view.offset.x;
}
}
}