ef23f465ce
# Objective _If I understand it correctly_, we were checking mesh visibility, as well as re-rendering point and spot light shadow maps for each view. This makes it so that M views and N lights produce M x N complexity. This PR aims to fix that, as well as introduce a stress test for this specific scenario. ## Solution - Keep track of what lights have already had mesh visibility calculated and do not calculate it again; - Reuse shadow depth textures and attachments across all views, and only render shadow maps for the _first_ time a light is encountered on a view; - Directional lights remain unaltered, since their shadow map cascades are view-dependent; - Add a new `many_cameras_lights` stress test example to verify the solution ## Showcase 110% speed up on the stress test 83% reduction of memory usage in stress test ### Before (5.35 FPS on stress test) <img width="1392" alt="Screenshot 2024-09-11 at 12 25 57" src="https://github.com/user-attachments/assets/136b0785-e9a4-44df-9a22-f99cc465e126"> ### After (11.34 FPS on stress test) <img width="1392" alt="Screenshot 2024-09-11 at 12 24 35" src="https://github.com/user-attachments/assets/b8dd858f-5e19-467f-8344-2b46ca039630"> ## Testing - Did you test these changes? If so, how? - On my game project where I have two cameras, and many shadow casting lights I managed to get pretty much double the FPS. - Also included a stress test, see the comparison above - Are there any parts that need more testing? - Yes, I would like help verifying that this fix is indeed correct, and that we were really re-rendering the shadow maps by mistake and it's indeed okay to not do that - How can other people (reviewers) test your changes? Is there anything specific they need to know? - Run the `many_cameras_lights` example - On the `main` branch, cherry pick the commit with the example (`git cherry-pick --no-commit 1ed4ace01`) and run it - If relevant, what platforms did you test these changes on, and are there any important ones you can't test? - macOS --------- Co-authored-by: François Mockers <francois.mockers@vleue.com>
93 lines
2.8 KiB
Rust
93 lines
2.8 KiB
Rust
//! Test rendering of many cameras and lights
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use std::f32::consts::PI;
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use bevy::{
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math::ops::{cos, sin},
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prelude::*,
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render::camera::Viewport,
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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_systems(Startup, setup)
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.add_systems(Update, rotate_cameras)
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.run();
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}
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const CAMERA_ROWS: usize = 4;
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const CAMERA_COLS: usize = 4;
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const NUM_LIGHTS: usize = 5;
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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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mut meshes: ResMut<Assets<Mesh>>,
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mut materials: ResMut<Assets<StandardMaterial>>,
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window: Query<&Window>,
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) {
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// circular base
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commands.spawn((
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Mesh3d(meshes.add(Circle::new(4.0))),
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MeshMaterial3d(materials.add(Color::WHITE)),
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Transform::from_rotation(Quat::from_rotation_x(-std::f32::consts::FRAC_PI_2)),
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));
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// cube
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commands.spawn((
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Mesh3d(meshes.add(Cuboid::new(1.0, 1.0, 1.0))),
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MeshMaterial3d(materials.add(Color::WHITE)),
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Transform::from_xyz(0.0, 0.5, 0.0),
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));
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// lights
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for i in 0..NUM_LIGHTS {
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let angle = (i as f32) / (NUM_LIGHTS as f32) * PI * 2.0;
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commands.spawn((
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PointLight {
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color: Color::hsv(angle.to_degrees(), 1.0, 1.0),
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intensity: 2_000_000.0 / NUM_LIGHTS as f32,
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shadows_enabled: true,
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..default()
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},
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Transform::from_xyz(sin(angle) * 4.0, 2.0, cos(angle) * 4.0),
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));
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}
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// cameras
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let window = window.single();
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let width = window.resolution.width() / CAMERA_COLS as f32 * window.resolution.scale_factor();
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let height = window.resolution.height() / CAMERA_ROWS as f32 * window.resolution.scale_factor();
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let mut i = 0;
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for y in 0..CAMERA_COLS {
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for x in 0..CAMERA_ROWS {
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let angle = i as f32 / (CAMERA_ROWS * CAMERA_COLS) as f32 * PI * 2.0;
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commands.spawn((
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Camera3d::default(),
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Camera {
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viewport: Some(Viewport {
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physical_position: UVec2::new(
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(x as f32 * width) as u32,
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(y as f32 * height) as u32,
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),
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physical_size: UVec2::new(width as u32, height as u32),
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..default()
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}),
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order: i,
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..default()
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},
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Transform::from_xyz(sin(angle) * 4.0, 2.5, cos(angle) * 4.0)
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.looking_at(Vec3::ZERO, Vec3::Y),
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));
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i += 1;
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}
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}
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}
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fn rotate_cameras(time: Res<Time>, mut query: Query<&mut Transform, With<Camera>>) {
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for mut transform in query.iter_mut() {
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transform.rotate_around(Vec3::ZERO, Quat::from_rotation_y(time.delta_secs()));
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}
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}
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