Struct OcclusionCulling

pub struct OcclusionCulling;

Add this component to a view in order to enable experimental GPU occlusion culling.

Bevy’s occlusion culling is currently marked as experimental. There are known issues whereby, in rare circumstances, occlusion culling can result in meshes being culled that shouldn’t be (i.e. meshes that turn invisible). Please try it out and report issues.

Occlusion culling allows Bevy to avoid rendering objects that are fully behind other opaque or alpha tested objects. This is different from, and complements, depth fragment rejection as the DepthPrepass enables. While depth rejection allows Bevy to avoid rendering pixels that are behind other objects, the GPU still has to examine those pixels to reject them, which requires transforming the vertices of the objects and performing skinning if the objects were skinned. Occlusion culling allows the GPU to go a step further, avoiding even transforming the vertices of objects that it can quickly prove to be behind other objects.

Occlusion culling inherently has some overhead, because Bevy must examine the objects’ bounding boxes, and create an acceleration structure (hierarchical Z-buffer) to perform the occlusion tests. Therefore, occlusion culling is disabled by default. Only enable it if you measure it to be a speedup on your scene. Note that, because Bevy’s occlusion culling runs on the GPU and is quite efficient, it’s rare for occlusion culling to result in a significant slowdown.

Occlusion culling currently requires a DepthPrepass. If no depth prepass is present on the view, the OcclusionCulling component will be ignored. Additionally, occlusion culling is currently incompatible with deferred shading; including both DeferredPrepass and OcclusionCulling results in unspecified behavior.

The algorithm that Bevy uses is known as two-phase occlusion culling. When you enable occlusion culling, Bevy splits the depth prepass into two: an early depth prepass and a late depth prepass. The early depth prepass renders all the meshes that were visible last frame to produce a conservative approximation of the depth buffer. Then, after producing an acceleration structure known as a hierarchical Z-buffer or depth pyramid, Bevy tests the bounding boxes of all meshes against that depth buffer. Those that can be quickly proven to be behind the geometry rendered during the early depth prepass are skipped entirely. The other potentially-visible meshes are rendered during the late prepass, and finally all the visible meshes are rendered as usual during the opaque, transparent, etc. passes.

Unlike other occlusion culling systems you may be familiar with, Bevy’s occlusion culling is fully dynamic and requires no baking step. The CPU overhead is minimal. Large skinned meshes and other dynamic objects can occlude other objects.

Trait Implementations

impl Clone for OcclusionCulling

fn clone(&self) -> OcclusionCulling

Returns a copy of the value.

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

Performs copy-assignment from source.

impl Component for OcclusionCulling

where OcclusionCulling: Send + Sync + 'static,

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, components: &mut ComponentsRegistrator<'_>, required_components: &mut RequiredComponents, inheritance_depth: u16, recursion_check_stack: &mut Vec<ComponentId>, )

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 register_component_hooks(hooks: &mut ComponentHooks)

👎Deprecated since 0.16.0: Use the individual hook methods instead (e.g., Component::on_add, etc.)

Called when registering this component, allowing mutable access to its ComponentHooks.

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 OcclusionCulling

fn default() -> OcclusionCulling

Returns the “default value” for a type.

impl ExtractComponent for OcclusionCulling

where OcclusionCulling: Clone,

type QueryData = &'static OcclusionCulling

ECS ReadOnlyQueryData to fetch the components to extract.

type QueryFilter = ()

Filters the entities with additional constraints.

type Out = OcclusionCulling

The output from extraction.

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

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

impl FromReflect for OcclusionCulling

where OcclusionCulling: Any + Send + Sync,

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

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 OcclusionCulling

where OcclusionCulling: Any + Send + Sync,

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 OcclusionCulling

where OcclusionCulling: Any + Send + Sync,

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<OcclusionCulling>) -> ReflectOwned

Returns an owned enumeration of “kinds” of type.

fn try_into_reflect( self: Box<OcclusionCulling>, ) -> 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<OcclusionCulling>) -> 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 clone_value(&self) -> Box<dyn PartialReflect>

👎Deprecated since 0.16.0: to clone reflected values, prefer using reflect_clone. To convert reflected values to dynamic ones, use to_dynamic.

Clones Self into its dynamic representation.

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

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

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 OcclusionCulling

where OcclusionCulling: Any + Send + Sync,

fn into_any(self: Box<OcclusionCulling>) -> 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<OcclusionCulling>) -> 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 OcclusionCulling

where OcclusionCulling: Any + Send + Sync,

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

fn clone_dynamic(&self) -> DynamicStruct

👎Deprecated since 0.16.0: use to_dynamic_struct instead

Clones the struct into a DynamicStruct.

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

Will return None if TypeInfo is not available.

impl TypePath for OcclusionCulling

where OcclusionCulling: Any + Send + Sync,

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 OcclusionCulling

where OcclusionCulling: Any + Send + Sync,

fn type_info() -> &'static TypeInfo

Returns the compile-time info for the underlying type.

impl Copy for OcclusionCulling