New Exposure and Lighting Defaults (and calibrate examples) (#11868)

# Objective

After adding configurable exposure, we set the default ev100 value to
`7` (indoor). This brought us out of sync with Blender's configuration
and defaults. This PR changes the default to `9.7` (bright indoor or
very overcast outdoors), as I calibrated in #11577. This feels like a
very reasonable default.

The other changes generally center around tweaking Bevy's lighting
defaults and examples to play nicely with this number, alongside a few
other tweaks and improvements.

Note that for artistic reasons I have reverted some examples, which
changed to directional lights in #11581, back to point lights.
 
Fixes #11577 

---

## Changelog

- Changed `Exposure::ev100` from `7` to `9.7` to better match Blender
- Renamed `ExposureSettings` to `Exposure`
- `Camera3dBundle` now includes `Exposure` for discoverability
- Bumped `FULL_DAYLIGHT ` and `DIRECT_SUNLIGHT` to represent the
middle-to-top of those ranges instead of near the bottom
- Added new `AMBIENT_DAYLIGHT` constant and set that as the new
`DirectionalLight` default illuminance.
- `PointLight` and `SpotLight` now have a default `intensity` of
1,000,000 lumens. This makes them actually useful in the context of the
new "semi-outdoor" exposure and puts them in the "cinema lighting"
category instead of the "common household light" category. They are also
reasonably close to the Blender default.
- `AmbientLight` default has been bumped from `20` to `80`.

## Migration Guide

- The increased `Exposure::ev100` means that all existing 3D lighting
will need to be adjusted to match (DirectionalLights, PointLights,
SpotLights, EnvironmentMapLights, etc). Or alternatively, you can adjust
the `Exposure::ev100` on your cameras to work nicely with your current
lighting values. If you are currently relying on default intensity
values, you might need to change the intensity to achieve the same
effect. Note that in Bevy 0.12, point/spot lights had a different hard
coded ev100 value than directional lights. In Bevy 0.13, they use the
same ev100, so if you have both in your scene, the _scale_ between these
light types has changed and you will likely need to adjust one or both
of them.

crates/bevy_core_pipeline/src/core_3d/camera_3d.rs

@@ -2,7 +2,7 @@ use crate::tonemapping::{DebandDither, Tonemapping};
 use bevy_ecs::prelude::*;
 use bevy_reflect::{Reflect, ReflectDeserialize, ReflectSerialize};
 use bevy_render::{
- camera::{Camera, CameraMainTextureUsages, CameraRenderGraph, Projection},
+ camera::{Camera, CameraMainTextureUsages, CameraRenderGraph, Exposure, Projection},
  extract_component::ExtractComponent,
  primitives::Frustum,
  render_resource::{LoadOp, TextureUsages},
@@ -145,6 +145,7 @@ pub struct Camera3dBundle {
  pub tonemapping: Tonemapping,
  pub dither: DebandDither,
  pub color_grading: ColorGrading,
+ pub exposure: Exposure,
  pub main_texture_usages: CameraMainTextureUsages,
 }
 
@@ -161,9 +162,10 @@ impl Default for Camera3dBundle {
  global_transform: Default::default(),
  camera_3d: Default::default(),
  tonemapping: Default::default(),
- dither: DebandDither::Enabled,
- color_grading: ColorGrading::default(),
+ color_grading: Default::default(),
+ exposure: Default::default(),
  main_texture_usages: Default::default(),
+ dither: DebandDither::Enabled,
  }
  }
 }

crates/bevy_core_pipeline/src/skybox/mod.rs

@@ -7,7 +7,7 @@ use bevy_ecs::{
  system::{Commands, Query, Res, ResMut, Resource},
 };
 use bevy_render::{
- camera::ExposureSettings,
+ camera::Exposure,
  extract_component::{
  ComponentUniforms, DynamicUniformIndex, ExtractComponent, ExtractComponentPlugin,
  UniformComponentPlugin,
@@ -80,16 +80,14 @@ pub struct Skybox {
 }
 
 impl ExtractComponent for Skybox {
- type QueryData = (&'static Self, Option<&'static ExposureSettings>);
+ type QueryData = (&'static Self, Option<&'static Exposure>);
  type QueryFilter = ();
  type Out = (Self, SkyboxUniforms);
 
- fn extract_component(
- (skybox, exposure_settings): QueryItem<'_, Self::QueryData>,
- ) -> Option<Self::Out> {
- let exposure = exposure_settings
+ fn extract_component((skybox, exposure): QueryItem<'_, Self::QueryData>) -> Option<Self::Out> {
+ let exposure = exposure
  .map(|e| e.exposure())
- .unwrap_or_else(|| ExposureSettings::default().exposure());
+ .unwrap_or_else(|| Exposure::default().exposure());
 
  Some((
  skybox.clone(),

crates/bevy_pbr/src/light.rs

@@ -69,10 +69,12 @@ pub mod light_consts {
  pub const CLEAR_SUNRISE: f32 = 400.;
  /// The amount of light (lux) on a overcast day; typical TV studio lighting
  pub const OVERCAST_DAY: f32 = 1000.;
+ /// The amount of light (lux) from ambient daylight (not direct sunlight).
+ pub const AMBIENT_DAYLIGHT: f32 = 10_000.;
  /// The amount of light (lux) in full daylight (not direct sun).
- pub const FULL_DAYLIGHT: f32 = 10_000.;
+ pub const FULL_DAYLIGHT: f32 = 20_000.;
  /// The amount of light (lux) in direct sunlight.
- pub const DIRECT_SUNLIGHT: f32 = 50_000.;
+ pub const DIRECT_SUNLIGHT: f32 = 100_000.;
  }
 }
 
@@ -113,7 +115,10 @@ impl Default for PointLight {
  fn default() -> Self {
  PointLight {
  color: Color::rgb(1.0, 1.0, 1.0),
- intensity: 2000.0, // Roughly a 20-watt LED bulb
+ // 1,000,000 lumens is a very large "cinema light" capable of registering brightly at Bevy's
+ // default "very overcast day" exposure level. For "indoor lighting" with a lower exposure,
+ // this would be way too bright.
+ intensity: 1_000_000.0,
  range: 20.0,
  radius: 0.0,
  shadows_enabled: false,
@@ -181,7 +186,10 @@ impl Default for SpotLight {
  // a quarter arc attenuating from the center
  Self {
  color: Color::rgb(1.0, 1.0, 1.0),
- intensity: 2000.0, // Roughly a 20-watt LED bulb
+ // 1,000,000 lumens is a very large "cinema light" capable of registering brightly at Bevy's
+ // default "very overcast day" exposure level. For "indoor lighting" with a lower exposure,
+ // this would be way too bright.
+ intensity: 1_000_000.0,
  range: 20.0,
  radius: 0.0,
  shadows_enabled: false,
@@ -262,7 +270,7 @@ impl Default for DirectionalLight {
  fn default() -> Self {
  DirectionalLight {
  color: Color::rgb(1.0, 1.0, 1.0),
- illuminance: light_consts::lux::OVERCAST_DAY,
+ illuminance: light_consts::lux::AMBIENT_DAYLIGHT,
  shadows_enabled: false,
  shadow_depth_bias: Self::DEFAULT_SHADOW_DEPTH_BIAS,
  shadow_normal_bias: Self::DEFAULT_SHADOW_NORMAL_BIAS,
@@ -637,7 +645,7 @@ impl Default for AmbientLight {
  fn default() -> Self {
  Self {
  color: Color::WHITE,
- brightness: 20.0,
+ brightness: 80.0,
  }
  }
 }

crates/bevy_render/src/camera/camera.rs

@@ -90,12 +90,12 @@ pub struct ComputedCameraValues {
 ///
 /// <https://en.wikipedia.org/wiki/Exposure_(photography)>
 #[derive(Component)]
-pub struct ExposureSettings {
+pub struct Exposure {
  /// <https://en.wikipedia.org/wiki/Exposure_value#Tabulated_exposure_values>
  pub ev100: f32,
 }
 
-impl ExposureSettings {
+impl Exposure {
  pub const SUNLIGHT: Self = Self {
  ev100: Self::EV100_SUNLIGHT,
  };
@@ -105,11 +105,24 @@ impl ExposureSettings {
  pub const INDOOR: Self = Self {
  ev100: Self::EV100_INDOOR,
  };
+ /// This value was calibrated to match Blender's implicit/default exposure as closely as possible.
+ /// It also happens to be a reasonable default.
+ ///
+ /// See <https:/bevyengine/bevy/issues/11577> for details.
+ pub const BLENDER: Self = Self {
+ ev100: Self::EV100_BLENDER,
+ };
 
  pub const EV100_SUNLIGHT: f32 = 15.0;
  pub const EV100_OVERCAST: f32 = 12.0;
  pub const EV100_INDOOR: f32 = 7.0;
 
+ /// This value was calibrated to match Blender's implicit/default exposure as closely as possible.
+ /// It also happens to be a reasonable default.
+ ///
+ /// See <https:/bevyengine/bevy/issues/11577> for details.
+ pub const EV100_BLENDER: f32 = 9.7;
+
  pub fn from_physical_camera(physical_camera_parameters: PhysicalCameraParameters) -> Self {
  Self {
  ev100: physical_camera_parameters.ev100(),
@@ -124,14 +137,14 @@ impl ExposureSettings {
  }
 }
 
-impl Default for ExposureSettings {
+impl Default for Exposure {
  fn default() -> Self {
- Self::INDOOR
+ Self::BLENDER
  }
 }
 
 /// Parameters based on physical camera characteristics for calculating
-/// EV100 values for use with [`ExposureSettings`].
+/// EV100 values for use with [`Exposure`].
 #[derive(Clone, Copy)]
 pub struct PhysicalCameraParameters {
  /// <https://en.wikipedia.org/wiki/F-number>
@@ -798,7 +811,7 @@ pub fn extract_cameras(
  &VisibleEntities,
  &Frustum,
  Option<&ColorGrading>,
- Option<&ExposureSettings>,
+ Option<&Exposure>,
  Option<&TemporalJitter>,
  Option<&RenderLayers>,
  Option<&Projection>,
@@ -815,7 +828,7 @@ pub fn extract_cameras(
  visible_entities,
  frustum,
  color_grading,
- exposure_settings,
+ exposure,
  temporal_jitter,
  render_layers,
  projection,
@@ -858,9 +871,9 @@ pub fn extract_cameras(
  clear_color: camera.clear_color.clone(),
  // this will be set in sort_cameras
  sorted_camera_index_for_target: 0,
- exposure: exposure_settings
+ exposure: exposure
  .map(|e| e.exposure())
- .unwrap_or_else(|| ExposureSettings::default().exposure()),
+ .unwrap_or_else(|| Exposure::default().exposure()),
  },
  ExtractedView {
  projection: camera.projection_matrix(),

crates/bevy_render/src/view/mod.rs

@@ -7,7 +7,7 @@ pub use window::*;
 
 use crate::{
  camera::{
- CameraMainTextureUsages, ClearColor, ClearColorConfig, ExposureSettings, ExtractedCamera,
+ CameraMainTextureUsages, ClearColor, ClearColorConfig, Exposure, ExtractedCamera,
  ManualTextureViews, MipBias, TemporalJitter,
  },
  extract_resource::{ExtractResource, ExtractResourcePlugin},
@@ -434,7 +434,7 @@ pub fn prepare_view_uniforms(
  world_position: extracted_view.transform.translation(),
  exposure: extracted_camera
  .map(|c| c.exposure)
- .unwrap_or_else(|| ExposureSettings::default().exposure()),
+ .unwrap_or_else(|| Exposure::default().exposure()),
  viewport,
  frustum,
  color_grading: extracted_view.color_grading,

examples/3d/3d_gizmos.rs

@@ -41,13 +41,12 @@ fn setup(
  ..default()
  });
  // light
- commands.spawn(DirectionalLightBundle {
- directional_light: DirectionalLight {
- illuminance: light_consts::lux::OVERCAST_DAY,
+ commands.spawn(PointLightBundle {
+ point_light: PointLight {
  shadows_enabled: true,
  ..default()
  },
- transform: Transform::from_xyz(4.0, 8.0, 4.0).looking_at(Vec3::ZERO, Vec3::Y),
+ transform: Transform::from_xyz(4.0, 8.0, 4.0),
  ..default()
  });
 

examples/3d/3d_scene.rs

@@ -30,13 +30,12 @@ fn setup(
  ..default()
  });
  // light
- commands.spawn(DirectionalLightBundle {
- directional_light: DirectionalLight {
- illuminance: light_consts::lux::OVERCAST_DAY,
+ commands.spawn(PointLightBundle {
+ point_light: PointLight {
  shadows_enabled: true,
  ..default()
  },
- transform: Transform::from_xyz(4.0, 8.0, 4.0).looking_at(Vec3::ZERO, Vec3::Y),
+ transform: Transform::from_xyz(4.0, 8.0, 4.0),
  ..default()
  });
  // camera

examples/3d/3d_shapes.rs

@@ -64,13 +64,14 @@ fn setup(
  ));
  }
 
- commands.spawn(DirectionalLightBundle {
- directional_light: DirectionalLight {
- illuminance: light_consts::lux::OVERCAST_DAY,
+ commands.spawn(PointLightBundle {
+ point_light: PointLight {
  shadows_enabled: true,
+ intensity: 10_000_000.,
+ range: 100.0,
  ..default()
  },
- transform: Transform::from_xyz(8.0, 16.0, 8.0).looking_at(Vec3::ZERO, Vec3::Y),
+ transform: Transform::from_xyz(8.0, 16.0, 8.0),
  ..default()
  });
 

examples/3d/3d_viewport_to_world.rs

@@ -66,7 +66,6 @@ fn setup(
  // light
  commands.spawn(DirectionalLightBundle {
  transform: Transform::from_translation(Vec3::ONE).looking_at(Vec3::ZERO, Vec3::Y),
- directional_light: DirectionalLight::default(),
  ..default()
  });
 

examples/3d/animated_material.rs

@@ -25,7 +25,7 @@ fn setup(
  EnvironmentMapLight {
  diffuse_map: asset_server.load("environment_maps/pisa_diffuse_rgb9e5_zstd.ktx2"),
  specular_map: asset_server.load("environment_maps/pisa_specular_rgb9e5_zstd.ktx2"),
- intensity: 1_000.0,
+ intensity: 2_000.0,
  },
  ));
 

examples/3d/anti_aliasing.rs

@@ -289,7 +289,7 @@ fn setup(
  // Light
  commands.spawn(DirectionalLightBundle {
  directional_light: DirectionalLight {
- illuminance: light_consts::lux::OVERCAST_DAY,
+ illuminance: light_consts::lux::FULL_DAYLIGHT,
  shadows_enabled: true,
  ..default()
  },

examples/3d/atmospheric_fog.rs

@@ -61,7 +61,6 @@ fn setup_terrain_scene(
  commands.spawn(DirectionalLightBundle {
  directional_light: DirectionalLight {
  color: Color::rgb(0.98, 0.95, 0.82),
- illuminance: light_consts::lux::OVERCAST_DAY,
  shadows_enabled: true,
  ..default()
  },

examples/3d/blend_modes.rs

@@ -167,12 +167,8 @@ fn setup(
  }
 
  // Light
- commands.spawn(DirectionalLightBundle {
- directional_light: DirectionalLight {
- illuminance: light_consts::lux::OVERCAST_DAY,
- ..default()
- },
- transform: Transform::from_xyz(4.0, 8.0, 4.0).looking_at(Vec3::ZERO, Vec3::Y),
+ commands.spawn(PointLightBundle {
+ transform: Transform::from_xyz(4.0, 8.0, 4.0),
  ..default()
  });
 

examples/3d/deferred_rendering.rs

@@ -58,7 +58,7 @@ fn setup(
  EnvironmentMapLight {
  diffuse_map: asset_server.load("environment_maps/pisa_diffuse_rgb9e5_zstd.ktx2"),
  specular_map: asset_server.load("environment_maps/pisa_specular_rgb9e5_zstd.ktx2"),
- intensity: 250.0,
+ intensity: 2000.0,
  },
  DepthPrepass,
  MotionVectorPrepass,
@@ -68,7 +68,7 @@ fn setup(
 
  commands.spawn(DirectionalLightBundle {
  directional_light: DirectionalLight {
- illuminance: light_consts::lux::OVERCAST_DAY,
+ illuminance: 15_000.,
  shadows_enabled: true,
  ..default()
  },
@@ -140,7 +140,7 @@ fn setup(
  // Light
  commands.spawn(PointLightBundle {
  point_light: PointLight {
- intensity: 150.0,
+ intensity: 800.0,
  radius: 0.125,
  shadows_enabled: true,
  color: sphere_color,

examples/3d/fog.rs

@@ -17,7 +17,6 @@
 use bevy::{
  pbr::{NotShadowCaster, NotShadowReceiver},
  prelude::*,
- render::camera::ExposureSettings,
 };
 
 fn main() {
@@ -43,9 +42,6 @@ fn setup_camera_fog(mut commands: Commands) {
  },
  ..default()
  },
- // This is a dark scene,
- // increasing the exposure makes it easier to see
- ExposureSettings { ev100: 4.0 },
  ));
 }
 
@@ -119,7 +115,6 @@ fn setup_pyramid_scene(
  commands.spawn(PointLightBundle {
  transform: Transform::from_xyz(0.0, 1.0, 0.0),
  point_light: PointLight {
- intensity: 4_000.,
  shadows_enabled: true,
  ..default()
  },

examples/3d/generate_custom_mesh.rs

@@ -57,11 +57,7 @@ fn setup(
  });
 
  // Light up the scene.
- commands.spawn(DirectionalLightBundle {
- directional_light: DirectionalLight {
- illuminance: light_consts::lux::OVERCAST_DAY,
- ..default()
- },
+ commands.spawn(PointLightBundle {
  transform: camera_and_light_transform,
  ..default()
  });