Struct AutoExposure 

pub struct AutoExposure {
    pub range: RangeInclusive<f32>,
    pub filter: RangeInclusive<f32>,
    pub speed_brighten: f32,
    pub speed_darken: f32,
    pub exponential_transition_distance: f32,
    pub metering_mask: Handle<Image>,
    pub compensation_curve: Handle<AutoExposureCompensationCurve>,
}

Component that enables auto exposure for an HDR-enabled 2d or 3d camera.

Auto exposure adjusts the exposure of the camera automatically to simulate the human eye’s ability to adapt to different lighting conditions.

Bevy’s implementation builds a 64 bin histogram of the scene’s luminance, and then adjusts the exposure so that the average brightness of the final render will be middle gray. Because it’s using a histogram, some details can be selectively ignored or emphasized. Outliers like shadows and specular highlights can be ignored, and certain areas can be given more (or less) weight based on a mask.

Usage Notes

Auto Exposure requires compute shaders and is not compatible with WebGL2.

Fields

range: RangeInclusive<f32>

The range of exposure values for the histogram.

Pixel values below this range will be ignored, and pixel values above this range will be clamped in the sense that they will count towards the highest bin in the histogram. The default value is -8.0..=8.0.

filter: RangeInclusive<f32>

The portion of the histogram to consider when metering.

By default, the darkest 10% and the brightest 10% of samples are ignored, so the default value is 0.10..=0.90.

speed_brighten: f32

The speed at which the exposure adapts from dark to bright scenes, in F-stops per second.

speed_darken: f32

The speed at which the exposure adapts from bright to dark scenes, in F-stops per second.

exponential_transition_distance: f32

The distance in F-stops from the target exposure from where to transition from animating in linear fashion to animating exponentially. This helps against jittering when the target exposure keeps on changing slightly from frame to frame, while still maintaining a relatively slow animation for big changes in scene brightness.

ev
                      ➔●┐
|              ⬈         ├ exponential section
│        ⬈               ┘
│    ⬈                   ┐
│  ⬈                     ├ linear section
│⬈                       ┘
●───────────────────────── time

The default value is 1.5.

metering_mask: Handle<Image>

The mask to apply when metering. The mask will cover the entire screen, where:

• (0.0, 0.0) is the top-left corner,
• (1.0, 1.0) is the bottom-right corner.

Only the red channel of the texture is used. The sample at the current screen position will be used to weight the contribution of each pixel to the histogram:

• 0.0 means the pixel will not contribute to the histogram,
• 1.0 means the pixel will contribute fully to the histogram.

The default value is a white image, so all pixels contribute equally.

Usage Notes

The mask is quantized to 16 discrete levels because of limitations in the compute shader implementation.

compensation_curve: Handle<AutoExposureCompensationCurve>

Exposure compensation curve to apply after metering. The default value is a flat line at 0.0. For more information, see AutoExposureCompensationCurve.

Trait Implementations

impl Clone for AutoExposure

fn clone(&self) -> AutoExposure

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Component for AutoExposure

where AutoExposure: Send + Sync + 'static,

Required Components: Hdr.

A component’s Required Components are inserted whenever it is inserted. Note that this will also insert the required components of the required components, recursively, in depth-first order.

const STORAGE_TYPE: StorageType = bevy_ecs::component::StorageType::Table

A constant indicating the storage type used for this component.

type Mutability = Mutable

A marker type to assist Bevy with determining if this component is mutable, or immutable. Mutable components will have Component<Mutability = Mutable>, while immutable components will instead have Component<Mutability = Immutable>.

fn register_required_components( _requiree: ComponentId, required_components: &mut RequiredComponentsRegistrator<'_, '_>, )

Registers required components.

fn clone_behavior() -> ComponentCloneBehavior

Called when registering this component, allowing to override clone function (or disable cloning altogether) for this component.

fn on_add() -> Option<for<'w> fn(DeferredWorld<'w>, HookContext)>

Gets the on_add ComponentHook for this Component if one is defined.

fn on_insert() -> Option<for<'w> fn(DeferredWorld<'w>, HookContext)>

Gets the on_insert ComponentHook for this Component if one is defined.

fn on_replace() -> Option<for<'w> fn(DeferredWorld<'w>, HookContext)>

Gets the on_replace ComponentHook for this Component if one is defined.

fn on_remove() -> Option<for<'w> fn(DeferredWorld<'w>, HookContext)>

Gets the on_remove ComponentHook for this Component if one is defined.

fn on_despawn() -> Option<for<'w> fn(DeferredWorld<'w>, HookContext)>

Gets the on_despawn ComponentHook for this Component if one is defined.

fn map_entities<E>(_this: &mut Self, _mapper: &mut E)

where E: EntityMapper,

Maps the entities on this component using the given EntityMapper. This is used to remap entities in contexts like scenes and entity cloning. When deriving Component, this is populated by annotating fields containing entities with #[entities]

impl Default for AutoExposure

fn default() -> AutoExposure

Returns the “default value” for a type.

impl ExtractComponent for AutoExposure

where AutoExposure: Clone,

type QueryData = &'static AutoExposure

ECS ReadOnlyQueryData to fetch the components to extract.

type QueryFilter = ()

Filters the entities with additional constraints.

type Out = AutoExposure

The output from extraction.

fn extract_component( item: <<AutoExposure as ExtractComponent>::QueryData as QueryData>::Item<'_, '_>, ) -> Option<<AutoExposure as ExtractComponent>::Out>

Defines how the component is transferred into the “render world”.

impl FromReflect for AutoExposure

fn from_reflect( reflect: &(dyn PartialReflect + 'static), ) -> Option<AutoExposure>

Constructs a concrete instance of Self from a reflected value.

fn take_from_reflect( reflect: Box<dyn PartialReflect>, ) -> Result<Self, Box<dyn PartialReflect>>

Attempts to downcast the given value to Self using, constructing the value using from_reflect if that fails.

impl GetTypeRegistration for AutoExposure

fn get_type_registration() -> TypeRegistration

Returns the default TypeRegistration for this type.

fn register_type_dependencies(registry: &mut TypeRegistry)

Registers other types needed by this type.

impl PartialReflect for AutoExposure

fn get_represented_type_info(&self) -> Option<&'static TypeInfo>

Returns the TypeInfo of the type represented by this value.

fn try_apply( &mut self, value: &(dyn PartialReflect + 'static), ) -> Result<(), ApplyError>

Tries to apply a reflected value to this value.

fn reflect_kind(&self) -> ReflectKind

Returns a zero-sized enumeration of “kinds” of type.

fn reflect_ref(&self) -> ReflectRef<'_>

Returns an immutable enumeration of “kinds” of type.

fn reflect_mut(&mut self) -> ReflectMut<'_>

Returns a mutable enumeration of “kinds” of type.

fn reflect_owned(self: Box<AutoExposure>) -> ReflectOwned

Returns an owned enumeration of “kinds” of type.

fn try_into_reflect( self: Box<AutoExposure>, ) -> Result<Box<dyn Reflect>, Box<dyn PartialReflect>>

Attempts to cast this type to a boxed, fully-reflected value.

fn try_as_reflect(&self) -> Option<&(dyn Reflect + 'static)>

Attempts to cast this type to a fully-reflected value.

fn try_as_reflect_mut(&mut self) -> Option<&mut (dyn Reflect + 'static)>

Attempts to cast this type to a mutable, fully-reflected value.

fn into_partial_reflect(self: Box<AutoExposure>) -> Box<dyn PartialReflect>

Casts this type to a boxed, reflected value.

fn as_partial_reflect(&self) -> &(dyn PartialReflect + 'static)

Casts this type to a reflected value.

fn as_partial_reflect_mut(&mut self) -> &mut (dyn PartialReflect + 'static)

Casts this type to a mutable, reflected value.

fn reflect_partial_eq( &self, value: &(dyn PartialReflect + 'static), ) -> Option<bool>

Returns a “partial equality” comparison result.

fn reflect_clone(&self) -> Result<Box<dyn Reflect>, ReflectCloneError>

Attempts to clone Self using reflection.

fn apply(&mut self, value: &(dyn PartialReflect + 'static))

Applies a reflected value to this value.

fn to_dynamic(&self) -> Box<dyn PartialReflect>

Converts this reflected value into its dynamic representation based on its kind.

fn reflect_clone_and_take<T>(&self) -> Result<T, ReflectCloneError>

where T: 'static, Self: Sized + TypePath,

For a type implementing PartialReflect, combines reflect_clone and take in a useful fashion, automatically constructing an appropriate ReflectCloneError if the downcast fails.

fn reflect_hash(&self) -> Option<u64>

Returns a hash of the value (which includes the type).

fn debug(&self, f: &mut Formatter<'_>) -> Result<(), Error>

Debug formatter for the value.

fn is_dynamic(&self) -> bool

Indicates whether or not this type is a dynamic type.

impl Reflect for AutoExposure

fn into_any(self: Box<AutoExposure>) -> Box<dyn Any>

Returns the value as a Box<dyn Any>.

fn as_any(&self) -> &(dyn Any + 'static)

Returns the value as a &dyn Any.

fn as_any_mut(&mut self) -> &mut (dyn Any + 'static)

Returns the value as a &mut dyn Any.

fn into_reflect(self: Box<AutoExposure>) -> Box<dyn Reflect>

Casts this type to a boxed, fully-reflected value.

fn as_reflect(&self) -> &(dyn Reflect + 'static)

Casts this type to a fully-reflected value.

fn as_reflect_mut(&mut self) -> &mut (dyn Reflect + 'static)

Casts this type to a mutable, fully-reflected value.

fn set(&mut self, value: Box<dyn Reflect>) -> Result<(), Box<dyn Reflect>>

Performs a type-checked assignment of a reflected value to this value.

impl Struct for AutoExposure

fn field(&self, name: &str) -> Option<&(dyn PartialReflect + 'static)>

Returns a reference to the value of the field named name as a &dyn PartialReflect.

fn field_mut( &mut self, name: &str, ) -> Option<&mut (dyn PartialReflect + 'static)>

Returns a mutable reference to the value of the field named name as a &mut dyn PartialReflect.

fn field_at(&self, index: usize) -> Option<&(dyn PartialReflect + 'static)>

Returns a reference to the value of the field with index index as a &dyn PartialReflect.

fn field_at_mut( &mut self, index: usize, ) -> Option<&mut (dyn PartialReflect + 'static)>

Returns a mutable reference to the value of the field with index index as a &mut dyn PartialReflect.

fn name_at(&self, index: usize) -> Option<&str>

Returns the name of the field with index index.

fn field_len(&self) -> usize

Returns the number of fields in the struct.

fn iter_fields(&self) -> FieldIter<'_>

Returns an iterator over the values of the reflectable fields for this struct.

fn to_dynamic_struct(&self) -> DynamicStruct

Creates a new DynamicStruct from this struct.

fn get_represented_struct_info(&self) -> Option<&'static StructInfo>

Will return None if TypeInfo is not available.

impl TypePath for AutoExposure

fn type_path() -> &'static str

Returns the fully qualified path of the underlying type.

fn short_type_path() -> &'static str

Returns a short, pretty-print enabled path to the type.

fn type_ident() -> Option<&'static str>

Returns the name of the type, or None if it is anonymous.

fn crate_name() -> Option<&'static str>

Returns the name of the crate the type is in, or None if it is anonymous.

fn module_path() -> Option<&'static str>

Returns the path to the module the type is in, or None if it is anonymous.

impl Typed for AutoExposure

fn type_info() -> &'static TypeInfo

Returns the compile-time info for the underlying type.