bevy/examples/3d/orthographic_pipelined.rs
Robert Swain 045f324e97 Use the infinite reverse right-handed perspective projection (#2543)
# Objective

Forward perspective projections have poor floating point precision distribution over the depth range. Reverse projections fair much better, and instead of having to have a far plane, with the reverse projection, using an infinite far plane is not a problem. The infinite reverse perspective projection has become the industry standard. The renderer rework is a great time to migrate to it.

## Solution

All perspective projections, including point lights, have been moved to using `glam::Mat4::perspective_infinite_reverse_rh()` and so have no far plane. As various depth textures are shared between orthographic and perspective projections, a quirk of this PR is that the near and far planes of the orthographic projection are swapped when the Mat4 is computed. This has no impact on 2D/3D orthographic projection usage, and provides consistency in shaders, texture clear values, etc. throughout the codebase.

## Known issues

For some reason, when looking along -Z, all geometry is black. The camera can be translated up/down / strafed left/right and geometry will still be black. Moving forward/backward or rotating the camera away from looking exactly along -Z causes everything to work as expected.

I have tried to debug this issue but both in macOS and Windows I get crashes when doing pixel debugging. If anyone could reproduce this and debug it I would be very grateful. Otherwise I will have to try to debug it further without pixel debugging, though the projections and such all looked fine to me.
2021-08-27 20:15:09 +00:00

71 lines
2.2 KiB
Rust

use bevy::{
ecs::prelude::*,
math::Vec3,
pbr2::{PbrBundle, PointLightBundle, StandardMaterial},
prelude::{App, Assets, Transform},
render2::{
camera::OrthographicCameraBundle,
color::Color,
mesh::{shape, Mesh},
},
PipelinedDefaultPlugins,
};
fn main() {
App::new()
.add_plugins(PipelinedDefaultPlugins)
.add_startup_system(setup.system())
.run();
}
/// set up a simple 3D scene
fn setup(
mut commands: Commands,
mut meshes: ResMut<Assets<Mesh>>,
mut materials: ResMut<Assets<StandardMaterial>>,
) {
// set up the camera
let mut camera = OrthographicCameraBundle::new_3d();
camera.orthographic_projection.scale = 3.0;
camera.transform = Transform::from_xyz(5.0, 5.0, 5.0).looking_at(Vec3::ZERO, Vec3::Y);
// camera
commands.spawn_bundle(camera);
// plane
commands.spawn_bundle(PbrBundle {
mesh: meshes.add(Mesh::from(shape::Plane { size: 5.0 })),
material: materials.add(Color::rgb(0.3, 0.5, 0.3).into()),
..Default::default()
});
// cubes
commands.spawn_bundle(PbrBundle {
mesh: meshes.add(Mesh::from(shape::Cube { size: 1.0 })),
material: materials.add(Color::rgb(0.8, 0.7, 0.6).into()),
transform: Transform::from_xyz(1.5, 0.5, 1.5),
..Default::default()
});
commands.spawn_bundle(PbrBundle {
mesh: meshes.add(Mesh::from(shape::Cube { size: 1.0 })),
material: materials.add(Color::rgb(0.8, 0.7, 0.6).into()),
transform: Transform::from_xyz(1.5, 0.5, -1.5),
..Default::default()
});
commands.spawn_bundle(PbrBundle {
mesh: meshes.add(Mesh::from(shape::Cube { size: 1.0 })),
material: materials.add(Color::rgb(0.8, 0.7, 0.6).into()),
transform: Transform::from_xyz(-1.5, 0.5, 1.5),
..Default::default()
});
commands.spawn_bundle(PbrBundle {
mesh: meshes.add(Mesh::from(shape::Cube { size: 1.0 })),
material: materials.add(Color::rgb(0.8, 0.7, 0.6).into()),
transform: Transform::from_xyz(-1.5, 0.5, -1.5),
..Default::default()
});
// light
commands.spawn_bundle(PointLightBundle {
transform: Transform::from_xyz(3.0, 8.0, 5.0),
..Default::default()
});
}