UCesiumSubLevelComponent Class Reference

A component intended to be attached to a Level Instance Actor that turns that Level Instance into a Cesium sub-level. More...

#include <CesiumSubLevelComponent.h>

Inheritance diagram for UCesiumSubLevelComponent:

Public Member Functions
bool	GetEnabled () const
	Gets whether this sub-level is enabled.
void	SetEnabled (bool value)
	Sets whether this sub-level is enabled.
double	GetOriginLongitude () const
	Gets the longitude of the georeference origin for this sub-level in degrees, in the range [-180, 180].
void	SetOriginLongitude (double value)
	Sets the longitude of the georeference origin for this sub-level in degrees, in the range [-180, 180].
double	GetOriginLatitude () const
	Gets the latitude of the georeference origin for this sub-level in degrees, in the range [-90, 90].
void	SetOriginLatitude (double value)
	Sets the latitude of the georeference origin for this sub-level in degrees, in the range [-90, 90].
double	GetOriginHeight () const
	Gets the height of the georeference origin for this sub-level in meters above the ellipsoid.
void	SetOriginHeight (double value)
	Sets the height of the georeference origin for this sub-level in meters above the ellipsoid.
double	GetLoadRadius () const
	Gets how close to the sub-level local origin, in meters, the camera needs to be to load the level.
void	SetLoadRadius (double value)
	Sets how close to the sub-level local origin, in meters, the camera needs to be to load the level.
TSoftObjectPtr< ACesiumGeoreference >	GetGeoreference () const
	Gets the designated georeference actor controlling how the actor's coordinate system relates to the coordinate system in this Unreal Engine level.
void	SetGeoreference (TSoftObjectPtr< ACesiumGeoreference > NewGeoreference)
	Sets the designated georeference actor controlling how the actor's coordinate system relates to the coordinate system in this Unreal Engine level.
ACesiumGeoreference *	GetResolvedGeoreference () const
	Gets the resolved georeference, just like calling the ResolveGeoreference property, except that it will return null if a georeference has not yet been resolved.
ACesiumGeoreference *	ResolveGeoreference (bool bForceReresolve=false)
	Resolves the Cesium Georeference to use with this components.
void	SetOriginLongitudeLatitudeHeight (const FVector &longitudeLatitudeHeight)
	Sets the longitude (X), latitude (Y), and height (Z) of this sub-level's georeference origin.
void	UpdateGeoreferenceIfSubLevelIsActive ()
	If this sub-level is currently the active one, this method will copy its origin to the georeference's origin.
virtual void	BeginDestroy () override
virtual void	OnComponentCreated () override

Protected Member Functions
virtual void	BeginPlay () override
virtual void	OnRegister () override
	Called when a component is registered.
virtual void	OnUnregister () override
	Called when a component is unregistered.

Detailed Description

A component intended to be attached to a Level Instance Actor that turns that Level Instance into a Cesium sub-level.

Only a single Cesium sub-level can be active (visible) at any given time.

A globe (like the planet Earth) is an unusual sort of level in Unreal in that it has truly massive coordinate values and the "up" direction depends on where exactly on the globe you're located. Many things in the Unreal ecosystem, such as the gravity system, don't expect this situation and will have incorrect and surprising behavior when used on a globe.

Cesium sub-levels help to mitigate this. Only one sub-level can be active at any given time, and when it is, that sub-level's origin becomes the origin of the Unreal world. Furthermore, at the origin location, Unreal's +X axis points East, its +Y axis points South, and its +Z axis points Up. Thus, within a sub-level, gravity works in the normal way that Unreal objects expect, and coordinate values stay relatively small. This allows you to use just about any Unreal object within a sub-level without worrying about surprising behavior.

Globe-aware objects, particularly those with a "Cesium Globe Anchor" component attached to them, are allowed to exist outside sub-levels and even move between them. If all your objects are globe aware, there's no need to use sub-levels at all.

In the Editor, the currently-active sub-level is selected by clicking the "Eye" icon next to the Level Instance in the Outliner.

At runtime, the currently-active sub-level is selected by the Actor with a CesiumOriginShiftComponent attached to it. If this Actor is inside a sub-level's "Load Radius" that sub-level will be activated. If multiple sub-levels are in range, only the closest one will be activated.

Definition at line 47 of file CesiumSubLevelComponent.h.

Member Function Documentation

BeginDestroy()

virtual void UCesiumSubLevelComponent::BeginDestroy ( )

overridevirtual

BeginPlay()

virtual void UCesiumSubLevelComponent::BeginPlay ( )

overrideprotectedvirtual

GetEnabled()

bool UCesiumSubLevelComponent::GetEnabled

(

)

const

Gets whether this sub-level is enabled.

An enabled sub-level will be automatically loaded when the camera moves within its LoadRadius and no other levels are closer, and the Georeference will be updated so that this level's Longitude, Latitude, and Height become (0, 0, 0) in the Unreal World. A sub-level that is not enabled will be ignored by Cesium at runtime.

GetGeoreference()

TSoftObjectPtr< ACesiumGeoreference > UCesiumSubLevelComponent::GetGeoreference

(

)

const

Gets the designated georeference actor controlling how the actor's coordinate system relates to the coordinate system in this Unreal Engine level.

If this is null, the sub-level will find and use the first Georeference Actor in the level, or create one if necessary. To get the active/effective Georeference from Blueprints or C++, use ResolvedGeoreference instead.

GetLoadRadius()

double UCesiumSubLevelComponent::GetLoadRadius

(

)

const

Gets how close to the sub-level local origin, in meters, the camera needs to be to load the level.

GetOriginHeight()

double UCesiumSubLevelComponent::GetOriginHeight

(

)

const

Gets the height of the georeference origin for this sub-level in meters above the ellipsoid.

This height should not be confused with a height above Mean Sea Level. When this sub-level is active, the CesiumGeoreference will adopt this origin.

GetOriginLatitude()

double UCesiumSubLevelComponent::GetOriginLatitude

(

)

const

Gets the latitude of the georeference origin for this sub-level in degrees, in the range [-90, 90].

When this sub-level is active, the CesiumGeoreference will adopt this origin.

GetOriginLongitude()

double UCesiumSubLevelComponent::GetOriginLongitude

(

)

const

Gets the longitude of the georeference origin for this sub-level in degrees, in the range [-180, 180].

When this sub-level is active, the CesiumGeoreference will adopt this origin.

GetResolvedGeoreference()

ACesiumGeoreference * UCesiumSubLevelComponent::GetResolvedGeoreference

(

)

const

Gets the resolved georeference, just like calling the ResolveGeoreference property, except that it will return null if a georeference has not yet been resolved.

OnComponentCreated()

virtual void UCesiumSubLevelComponent::OnComponentCreated ( )

overridevirtual

OnRegister()

virtual void UCesiumSubLevelComponent::OnRegister ( )

overrideprotectedvirtual

Called when a component is registered.

This can be viewed as "enabling" this Component on the Actor to which it is attached.

In the Editor, this is called in a many different situations, such as on changes to properties.

OnUnregister()

virtual void UCesiumSubLevelComponent::OnUnregister ( )

overrideprotectedvirtual

Called when a component is unregistered.

This can be viewed as "disabling" this Component on the Actor to which it is attached.

In the Editor, this is called in a many different situations, such as on changes to properties.

ResolveGeoreference()

ACesiumGeoreference * UCesiumSubLevelComponent::ResolveGeoreference

(

bool

bForceReresolve = false

)

Resolves the Cesium Georeference to use with this components.

Returns the value of the Georeference property if it is set. Otherwise, finds a Georeference in the World and returns it, creating it if necessary. The resolved Georeference is cached so subsequent calls to this function will return the same instance, unless ForceReresolve is true.

SetEnabled()

void UCesiumSubLevelComponent::SetEnabled

(

bool

value

)

Sets whether this sub-level is enabled.

An enabled sub-level will be automatically loaded when the camera moves within its LoadRadius and no other levels are closer, and the Georeference will be updated so that this level's Longitude, Latitude, and Height become (0, 0, 0) in the Unreal World. A sub-level that is not enabled will be ignored by Cesium at runtime.

SetGeoreference()

void UCesiumSubLevelComponent::SetGeoreference

(

TSoftObjectPtr< ACesiumGeoreference >

NewGeoreference

)

Sets the designated georeference actor controlling how the actor's coordinate system relates to the coordinate system in this Unreal Engine level.

If this is null, the sub-level will find and use the first Georeference Actor in the level, or create one if necessary. To get the active/effective Georeference from Blueprints or C++, use ResolvedGeoreference instead.

SetLoadRadius()

void UCesiumSubLevelComponent::SetLoadRadius

(

double

value

)

Sets how close to the sub-level local origin, in meters, the camera needs to be to load the level.

SetOriginHeight()

void UCesiumSubLevelComponent::SetOriginHeight

(

double

value

)

Sets the height of the georeference origin for this sub-level in meters above the ellipsoid.

This height should not be confused with a height above Mean Sea Level. When this sub-level is active, the CesiumGeoreference will adopt this origin.

SetOriginLatitude()

void UCesiumSubLevelComponent::SetOriginLatitude

(

double

value

)

Sets the latitude of the georeference origin for this sub-level in degrees, in the range [-90, 90].

When this sub-level is active, the CesiumGeoreference will adopt this origin.

SetOriginLongitude()

void UCesiumSubLevelComponent::SetOriginLongitude

(

double

value

)

Sets the longitude of the georeference origin for this sub-level in degrees, in the range [-180, 180].

When this sub-level is active, the CesiumGeoreference will adopt this origin.

SetOriginLongitudeLatitudeHeight()

void UCesiumSubLevelComponent::SetOriginLongitudeLatitudeHeight

(

const FVector &

longitudeLatitudeHeight

)

Sets the longitude (X), latitude (Y), and height (Z) of this sub-level's georeference origin.

When this sub-level is active, the CesiumGeoreference will adopt this origin. Longitude and latitude are in degrees. Height is in meters above the ellipsoid, which should not be confused with meters above Mean Sea Level.

UpdateGeoreferenceIfSubLevelIsActive()

void UCesiumSubLevelComponent::UpdateGeoreferenceIfSubLevelIsActive

(

)

If this sub-level is currently the active one, this method will copy its origin to the georeference's origin.

Otherwise, it does nothing.

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The documentation for this class was generated from the following file:

• Source/CesiumRuntime/Public/CesiumSubLevelComponent.h