UPolygonSelectionMechanic

[UPolygonSelectionMechanic](API\Plugins\ModelingComponents\Selection\UPolygonSelectionMechanic) implements the interaction for selecting a set of faces/vertices/edges from a FGroupTopology on a [UDynamicMeshComponent](API\Runtime\GeometryFramework\Components\UDynamicMeshComponent).

Choose your operating system:

Windows

macOS

Linux

Inheritance Hierarchy

UObjectBase

UObjectBaseUtility

UObject

UInteractionMechanic

UPolygonSelectionMechanic

References

Module	ModelingComponents
Header	/Engine/Plugins/Runtime/MeshModelingToolset/Source/ModelingComponents/Public/Selection/PolygonSelectionMechanic.h
Include	#include "Selection/PolygonSelectionMechanic.h"

Syntax

UCLASS()
class UPolygonSelectionMechanic :
    public UInteractionMechanic,
    public IClickBehaviorTarget,
    public IHoverBehaviorTarget

Remarks

UPolygonSelectionMechanic implements the interaction for selecting a set of faces/vertices/edges from a FGroupTopology on a UDynamicMeshComponent.

Variables

	Name	Description
TUniquePtr< FPo...	ActiveChange
bool	bAddSelectionFilterPropertiesToParentTool	Configuration variables that must be set before bSetup is called
FInputCapturePr...	BasePriority
bool	bCtrlToggle
bool	bIsEnabled
bool	bShiftToggle
FViewCameraStat...	CameraState
TObjectPtr< USi...	ClickOrDragBehavior
TSet< int >	CurrentlyHighlightedGroups
TObjectPtr< UTr...	DrawnTriangleSetComponent
TFunction< FDyn...	GetSpatialFunc
TObjectPtr< UMa...	HighlightedFaceMaterial
FToolDataVisual...	HilightRenderer
FGroupTopologyS...	HilightSelection
TObjectPtr< UMo...	HoverBehavior
FVector3d	LastClickedHitNormal
FVector3d	LastClickedHitPosition
TObjectPtr< URe...	MarqueeMechanic
const FDynamicM...	Mesh
FSimpleMulticas...	OnSelectionChanged	OnSelectionChanged is broadcast whenever the selection is modified (including by FChanges, which means that called functions should not issue undo transactions.
FGroupTopologyS...	PersistentSelection
FToolDataVisual...	PolyEdgesRenderer
FGroupTopologyS...	PreDragPersistentSelection	Used for box selection.
FGroupTopologyS...	PreDragTopoSelectorSettings
TObjectPtr< APr...	PreviewGeometryActor	The actor we create internally to own the DrawnTriangleSetComponent
TObjectPtr< UPo...	Properties	TODO: Is it worth issuing separate callbacks in normal selection changes and in FChange ones, to allow the user to bundle in some FChanges into the normal callback?
FToolDataVisual...	SelectionRenderer
int32	SelectionTimestamp
TFunction< bool...	ShouldAddToSelectionFunc
TFunction< bool...	ShouldRemoveFromSelectionFunc
TFunction< bool...	ShouldSelectEdgeLoopsFunc	When bSelectEdgeLoops is true, this function is tested to see if we should select edge loops, to allow edge loop selection to be toggled with some key (setting bSelectEdgeLoops to false overrides this function).
TFunction< bool...	ShouldSelectEdgeRingsFunc	When bSelectEdgeRings is true, this function is tested to see if we should select edge rings, to allow edge ring selection to be toggled with some key (setting bSelectEdgeRings to false overrides this function).
FTransform3d	TargetTransform
const FGroupTop...	Topology
TSharedPtr< FGr...	TopoSelector

Destructors

	Name	Description
	~UPolygonSelectionMechanic()

Functions

	Name	Description
void	BeginChange()	Change Tracking Begin a change record.
void	ClearHighlight()	Clear current hover-highlight
void	ClearSelection()	Clear the current selection.
void	DisableBehaviors ( UInteractiveTool* ParentToolIn )	Removes the mechanic's own click/hover handlers, which means that the parent tool will need to call UpdateSelection(), UpdateHighlight(), ClearHighlight(), and ClearSelection() from its own hover/click handlers.
void	DrawHUD ( FCanvas* Canvas, IToolsContextRenderAPI* Render... )
TUniquePtr< ...	EndChange()	End the active change and return it. Returns empty change if the selection was not modified!
bool	EndChangeAndEmitIfModified()	Ends the active change and emits it via the parent tool, if the selection has been modified.
const FGroup...	GetActiveSelection()
void	GetClickedHitPosition ( FVector3d& PositionOut, FVector3d& NormalOut )	Can be used by in an OnSelectionChanged event to inspect the clicked location (i.e., the values returned by the UpdateSelection() function when the click happened).
TPair< FInpu...	GetPriorityRange()	Gets the current priority range used by behaviors in the mechanic.
void	GetSelection ( UPersistentMeshSelection& Selectio..., const FCompactMaps* CompactMap... )	Gives the current selection as a storable selection object.
FAxisAligned...	GetSelectionBounds ( bool bWorld )
FFrame3d	GetSelectionFrame ( bool bWorld, FFrame3d* InitialLocalFrame )
TSharedPtr< ...	GetTopologySelector()
FGroupTopolo...	GetTopoSelectorSettings ( bool bUseOrthoSettings )	Get the topology selector settings to use given the current selection settings.
bool	HasSelection()
void	Initialize ( const FDynamicMesh3* Mesh, FTransform TargetTransform, UWorld* World, const FGroupTopology* Topology, TFunction< FDynamicMeshAABBTree3&#... )	Initializes the mechanic.
void	Initialize ( UDynamicMeshComponent* MeshCom..., const FGroupTopology* Topology, TFunction< FDynamicMeshAABBTree3&#... )
void	LoadSelection ( const UPersistentMeshSelection& Se... )	Sets the current selection using the given storable selection object.
void	NotifyMeshChanged ( bool bTopologyModified )	Notify internal data structures that the associated MeshComponent has been modified.
void	OnDragRectangleChanged ( const FCameraRectangle& CurrentRec... )
void	OnDragRectangleFinished ( const FCameraRectangle& Rectangle, bool bCancelled )
void	OnDragRectangleStarted()	These get bound to marquee mechanic delegates.
void	SetBasePriority ( const FInputCapturePriority& Prior... )	Sets the base priority so that tools can make sure that their own behaviors are higher priority.
void	SetIsEnabled ( bool bOn )	Enable/disable the mechanic without permanently removing behaviors or shutting it down.
void	SetSelection ( const FGroupTopologySelection& Sel..., bool bBroadcast )	Replace the current selection with an external selection.
void	SetShouldAddToSelectionFunc ( TFunction< bool)> Func )	By default, the shift key will cause new clicks to add to the selection.
void	SetShouldRemoveFromSelectionFunc ( TFunction< bool)> Func )	By default, the Ctrl key will cause new clicks to remove from the existing selection.
void	SetShouldSelectEdgeLoopsFunc ( TFunction< bool)> Func )
void	SetShouldSelectEdgeRingsFunc ( TFunction< bool)> Func )
bool	TopologyHitTest ( const FRay& WorldRay, FHitResult& OutHit, bool bUseOrthoSettings )	Perform a hit test on the topology using the current selection settings.
bool	TopologyHitTest ( const FRay& WorldRay, FHitResult& OutHit, FGroupTopologySelection& OutSelect..., bool bUseOrthoSettings )	Perform a hit test on the topology using the current selection settings.
bool	UpdateHighlight ( const FRay& WorldRay )	Hover API Update the hover highlight based on the hit elements at the given World Ray
void	UpdateMarqueeEnabled()
bool	UpdateSelection ( const FRay& WorldRay, FVector3d& LocalHitPositionOut, FVector3d& LocalHitNormalOut )	Selection API Intersect the ray with the mesh and update the selection based on the hit element, modifier states, etc

Overridden from UInteractionMechanic

	Name	Description
void	Render ( IToolsContextRenderAPI* Render... )	Allow the Mechanic to do any custom drawing (ie via PDI/RHI)
void	Setup ( UInteractiveTool* ParentTool )	Called to initialize the InteractionMechanic
void	Shutdown()	Called to clean up the InteractionMechanic

Overridden from IClickBehaviorTarget

		Name	Description
	FInputRayHit	IsHitByClick ( const FInputDeviceRay& ClickPos )	IClickBehaviorTarget implementation.
	void	OnClicked ( const FInputDeviceRay& ClickPos )	Notify Target that click ocurred

Overridden from IModifierToggleBehaviorTarget

		Name	Description
	void	OnUpdateModifierState ( int ModifierID, bool bIsOn )	Notify target of current modifier state

Overridden from IHoverBehaviorTarget

	Name	Description
FInputRayHit	BeginHoverSequenceHitTest ( const FInputDeviceRay& PressPos )	IHoverBehaviorTarget implementation.
void	OnBeginHover ( const FInputDeviceRay& DevicePos )	Initialize hover sequence at given position
void	OnEndHover()	Terminate active hover sequence
bool	OnUpdateHover ( const FInputDeviceRay& DevicePos )	Update active hover sequence with new input position

Typedefs

Name	Description
FAxisAlignedBox3d
FFrame3d
FTransform3d

Constants

Name	Description
CtrlModifierID
ShiftModifierID