bed9ddf3ce
# Objective - Fixes https://github.com/bevyengine/bevy/issues/16556 - Closes https://github.com/bevyengine/bevy/issues/11807 ## Solution - Simplify custom projections by using a single source of truth - `Projection`, removing all existing generic systems and types. - Existing perspective and orthographic structs are no longer components - I could dissolve these to simplify further, but keeping them around was the fast way to implement this. - Instead of generics, introduce a third variant, with a trait object. - Do an object safety dance with an intermediate trait to allow cloning boxed camera projections. This is a normal rust polymorphism papercut. You can do this with a crate but a manual impl is short and sweet. ## Testing - Added a custom projection example --- ## Showcase - Custom projections and projection handling has been simplified. - Projection systems are no longer generic, with the potential for many different projection components on the same camera. - Instead `Projection` is now the single source of truth for camera projections, and is the only projection component. - Custom projections are still supported, and can be constructed with `Projection::custom()`. ## Migration Guide - `PerspectiveProjection` and `OrthographicProjection` are no longer components. Use `Projection` instead. - Custom projections should no longer be inserted as a component. Instead, simply set the custom projection as a value of `Projection` with `Projection::custom()`.
85 lines
2.5 KiB
Rust
85 lines
2.5 KiB
Rust
//! Demonstrates how to define and use custom camera projections.
|
|
|
|
use bevy::prelude::*;
|
|
use bevy::render::camera::CameraProjection;
|
|
|
|
fn main() {
|
|
App::new()
|
|
.add_plugins(DefaultPlugins)
|
|
.add_systems(Startup, setup)
|
|
.run();
|
|
}
|
|
|
|
/// Like a perspective projection, but the vanishing point is not centered.
|
|
#[derive(Debug, Clone)]
|
|
struct ObliquePerspectiveProjection {
|
|
horizontal_obliqueness: f32,
|
|
vertical_obliqueness: f32,
|
|
perspective: PerspectiveProjection,
|
|
}
|
|
|
|
/// Implement the [`CameraProjection`] trait for our custom projection:
|
|
impl CameraProjection for ObliquePerspectiveProjection {
|
|
fn get_clip_from_view(&self) -> Mat4 {
|
|
let mut mat = self.perspective.get_clip_from_view();
|
|
mat.col_mut(2)[0] = self.horizontal_obliqueness;
|
|
mat.col_mut(2)[1] = self.vertical_obliqueness;
|
|
mat
|
|
}
|
|
|
|
fn get_clip_from_view_for_sub(&self, sub_view: &bevy_render::camera::SubCameraView) -> Mat4 {
|
|
let mut mat = self.perspective.get_clip_from_view_for_sub(sub_view);
|
|
mat.col_mut(2)[0] = self.horizontal_obliqueness;
|
|
mat.col_mut(2)[1] = self.vertical_obliqueness;
|
|
mat
|
|
}
|
|
|
|
fn update(&mut self, width: f32, height: f32) {
|
|
self.perspective.update(width, height);
|
|
}
|
|
|
|
fn far(&self) -> f32 {
|
|
self.perspective.far
|
|
}
|
|
|
|
fn get_frustum_corners(&self, z_near: f32, z_far: f32) -> [Vec3A; 8] {
|
|
self.perspective.get_frustum_corners(z_near, z_far)
|
|
}
|
|
}
|
|
|
|
fn setup(
|
|
mut commands: Commands,
|
|
mut meshes: ResMut<Assets<Mesh>>,
|
|
mut materials: ResMut<Assets<StandardMaterial>>,
|
|
) {
|
|
commands.spawn((
|
|
Camera3d::default(),
|
|
// Use our custom projection:
|
|
Projection::custom(ObliquePerspectiveProjection {
|
|
horizontal_obliqueness: 0.2,
|
|
vertical_obliqueness: 0.6,
|
|
perspective: PerspectiveProjection::default(),
|
|
}),
|
|
Transform::from_xyz(-2.5, 4.5, 9.0).looking_at(Vec3::ZERO, Vec3::Y),
|
|
));
|
|
|
|
// Scene setup
|
|
commands.spawn((
|
|
Mesh3d(meshes.add(Circle::new(4.0))),
|
|
MeshMaterial3d(materials.add(Color::WHITE)),
|
|
Transform::from_rotation(Quat::from_rotation_x(-std::f32::consts::FRAC_PI_2)),
|
|
));
|
|
commands.spawn((
|
|
Mesh3d(meshes.add(Cuboid::new(1.0, 1.0, 1.0))),
|
|
MeshMaterial3d(materials.add(Color::srgb_u8(124, 144, 255))),
|
|
Transform::from_xyz(0.0, 0.5, 0.0),
|
|
));
|
|
commands.spawn((
|
|
PointLight {
|
|
shadows_enabled: true,
|
|
..default()
|
|
},
|
|
Transform::from_xyz(4.0, 8.0, 4.0),
|
|
));
|
|
}
|