bevy/examples/3d/bloom_3d.rs
Marco Buono f87de36843 Send emissive color to uniform as linear instead of sRGB (#7897)
This produces more accurate results for the `EmissiveStrengthTest` glTF test case.

(Requires manually setting the emission, for now)

Before: <img width="1392" alt="Screenshot 2023-03-04 at 18 21 25" src="https://user-images.githubusercontent.com/418473/222929455-c7363d52-7133-4d4e-9d6a-562098f6bbe8.png">

After: <img width="1392" alt="Screenshot 2023-03-04 at 18 20 57" src="https://user-images.githubusercontent.com/418473/222929454-3ea20ecb-0773-4aad-978c-3832353b6871.png">

Tagging @JMS55 as a co-author, since this fix is based on their experiments with emission.

# Objective

- Have more accurate results for the `EmissiveStrengthTest` glTF test case.

## Solution

- Make sure we send the emissive color as linear instead of sRGB.

---

## Changelog

- Emission strength is now correctly interpreted by the `StandardMaterial` as linear instead of sRGB.

## Migration Guide

- If you have previously manually specified emissive values with `Color::rgb()` and would like to retain the old visual results, you must now use `Color::rgb_linear()` instead;
- If you have previously manually specified emissive values with `Color::rgb_linear()` and would like to retain the old visual results, you'll need to apply a one-time gamma calculation to your channels manually to get the _actual_ linear RGB value: 
  - For channel values greater than `0.0031308`, use `(1.055 * value.powf(1.0 / 2.4)) - 0.055`;
  - For channel values lower than or equal to `0.0031308`, use `value * 12.92`;
- Otherwise, the results should now be more consistent with other tools/engines.
2023-03-04 23:26:04 +00:00

248 lines
8.3 KiB
Rust

//! Illustrates bloom post-processing using HDR and emissive materials.
use bevy::{
core_pipeline::{
bloom::{BloomCompositeMode, BloomSettings},
tonemapping::Tonemapping,
},
prelude::*,
};
use std::{
collections::hash_map::DefaultHasher,
hash::{Hash, Hasher},
};
fn main() {
App::new()
.insert_resource(ClearColor(Color::DARK_GRAY))
.add_plugins(DefaultPlugins)
.add_startup_system(setup_scene)
.add_system(update_bloom_settings)
.add_system(bounce_spheres)
.run();
}
fn setup_scene(
mut commands: Commands,
mut meshes: ResMut<Assets<Mesh>>,
mut materials: ResMut<Assets<StandardMaterial>>,
asset_server: Res<AssetServer>,
) {
commands.spawn((
Camera3dBundle {
camera: Camera {
hdr: true, // 1. HDR is required for bloom
..default()
},
tonemapping: Tonemapping::TonyMcMapface, // 2. Using a tonemapper that desaturates to white is recommended
transform: Transform::from_xyz(-2.0, 2.5, 5.0).looking_at(Vec3::ZERO, Vec3::Y),
..default()
},
BloomSettings::default(), // 3. Enable bloom for the camera
));
let material_emissive1 = materials.add(StandardMaterial {
emissive: Color::rgb_linear(13.99, 5.32, 2.0), // 4. Put something bright in a dark environment to see the effect
..default()
});
let material_emissive2 = materials.add(StandardMaterial {
emissive: Color::rgb_linear(2.0, 13.99, 5.32),
..default()
});
let material_emissive3 = materials.add(StandardMaterial {
emissive: Color::rgb_linear(5.32, 2.0, 13.99),
..default()
});
let material_non_emissive = materials.add(StandardMaterial {
base_color: Color::GRAY,
..default()
});
let mesh = meshes.add(
shape::Icosphere {
radius: 0.5,
subdivisions: 5,
}
.try_into()
.unwrap(),
);
for x in -10..10 {
for z in -10..10 {
let mut hasher = DefaultHasher::new();
(x, z).hash(&mut hasher);
let rand = (hasher.finish() - 2) % 6;
let material = match rand {
0 => material_emissive1.clone(),
1 => material_emissive2.clone(),
2 => material_emissive3.clone(),
3 | 4 | 5 => material_non_emissive.clone(),
_ => unreachable!(),
};
commands.spawn((
PbrBundle {
mesh: mesh.clone(),
material,
transform: Transform::from_xyz(x as f32 * 2.0, 0.0, z as f32 * 2.0),
..default()
},
Bouncing,
));
}
}
commands.spawn(
TextBundle::from_section(
"",
TextStyle {
font: asset_server.load("fonts/FiraMono-Medium.ttf"),
font_size: 18.0,
color: Color::BLACK,
},
)
.with_style(Style {
position_type: PositionType::Absolute,
position: UiRect {
bottom: Val::Px(10.0),
left: Val::Px(10.0),
..default()
},
..default()
}),
);
}
// ------------------------------------------------------------------------------------------------
fn update_bloom_settings(
mut camera: Query<(Entity, Option<&mut BloomSettings>), With<Camera>>,
mut text: Query<&mut Text>,
mut commands: Commands,
keycode: Res<Input<KeyCode>>,
time: Res<Time>,
) {
let bloom_settings = camera.single_mut();
let mut text = text.single_mut();
let text = &mut text.sections[0].value;
match bloom_settings {
(entity, Some(mut bloom_settings)) => {
*text = "BloomSettings (Toggle: Space)\n".to_string();
text.push_str(&format!("(Q/A) Intensity: {}\n", bloom_settings.intensity));
text.push_str(&format!(
"(W/S) Low-frequency boost: {}\n",
bloom_settings.low_frequency_boost
));
text.push_str(&format!(
"(E/D) Low-frequency boost curvature: {}\n",
bloom_settings.low_frequency_boost_curvature
));
text.push_str(&format!(
"(R/F) High-pass frequency: {}\n",
bloom_settings.high_pass_frequency
));
text.push_str(&format!(
"(T/G) Mode: {}\n",
match bloom_settings.composite_mode {
BloomCompositeMode::EnergyConserving => "Energy-conserving",
BloomCompositeMode::Additive => "Additive",
}
));
text.push_str(&format!(
"(Y/H) Threshold: {}\n",
bloom_settings.prefilter_settings.threshold
));
text.push_str(&format!(
"(U/J) Threshold softness: {}\n",
bloom_settings.prefilter_settings.threshold_softness
));
if keycode.just_pressed(KeyCode::Space) {
commands.entity(entity).remove::<BloomSettings>();
}
let dt = time.delta_seconds();
if keycode.pressed(KeyCode::A) {
bloom_settings.intensity -= dt / 10.0;
}
if keycode.pressed(KeyCode::Q) {
bloom_settings.intensity += dt / 10.0;
}
bloom_settings.intensity = bloom_settings.intensity.clamp(0.0, 1.0);
if keycode.pressed(KeyCode::S) {
bloom_settings.low_frequency_boost -= dt / 10.0;
}
if keycode.pressed(KeyCode::W) {
bloom_settings.low_frequency_boost += dt / 10.0;
}
bloom_settings.low_frequency_boost = bloom_settings.low_frequency_boost.clamp(0.0, 1.0);
if keycode.pressed(KeyCode::D) {
bloom_settings.low_frequency_boost_curvature -= dt / 10.0;
}
if keycode.pressed(KeyCode::E) {
bloom_settings.low_frequency_boost_curvature += dt / 10.0;
}
bloom_settings.low_frequency_boost_curvature =
bloom_settings.low_frequency_boost_curvature.clamp(0.0, 1.0);
if keycode.pressed(KeyCode::F) {
bloom_settings.high_pass_frequency -= dt / 10.0;
}
if keycode.pressed(KeyCode::R) {
bloom_settings.high_pass_frequency += dt / 10.0;
}
bloom_settings.high_pass_frequency = bloom_settings.high_pass_frequency.clamp(0.0, 1.0);
if keycode.pressed(KeyCode::G) {
bloom_settings.composite_mode = BloomCompositeMode::Additive;
}
if keycode.pressed(KeyCode::T) {
bloom_settings.composite_mode = BloomCompositeMode::EnergyConserving;
}
if keycode.pressed(KeyCode::H) {
bloom_settings.prefilter_settings.threshold -= dt;
}
if keycode.pressed(KeyCode::Y) {
bloom_settings.prefilter_settings.threshold += dt;
}
bloom_settings.prefilter_settings.threshold =
bloom_settings.prefilter_settings.threshold.max(0.0);
if keycode.pressed(KeyCode::J) {
bloom_settings.prefilter_settings.threshold_softness -= dt / 10.0;
}
if keycode.pressed(KeyCode::U) {
bloom_settings.prefilter_settings.threshold_softness += dt / 10.0;
}
bloom_settings.prefilter_settings.threshold_softness = bloom_settings
.prefilter_settings
.threshold_softness
.clamp(0.0, 1.0);
}
(entity, None) => {
*text = "Bloom: Off (Toggle: Space)".to_string();
if keycode.just_pressed(KeyCode::Space) {
commands.entity(entity).insert(BloomSettings::default());
}
}
}
}
#[derive(Component)]
struct Bouncing;
fn bounce_spheres(time: Res<Time>, mut query: Query<&mut Transform, With<Bouncing>>) {
for mut transform in query.iter_mut() {
transform.translation.y =
(transform.translation.x + transform.translation.z + time.elapsed_seconds()).sin();
}
}