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  3. UModelingSelectionInteraction

UModelingSelectionInteraction

[UModelingSelectionInteraction](API\Plugins\ModelingToolsEditorMode\UModelingSelectionInteraction) provides element-level selection behavior (ie mesh triangles/edges/vertices) via the [UGeometrySelectionManager](API\Plugins\ModelingComponents\Selection\UGeometrySelectionManager).

API > API/Plugins > API/Plugins/ModelingToolsEditorMode

Inheritance Hierarchy

References

   
Module ModelingToolsEditorMode
Header /Engine/Plugins/Editor/ModelingToolsEditorMode/Source/ModelingToolsEditorMode/Public/ModelingSelectionInteraction.h
Include #include "ModelingSelectionInteraction.h"

Syntax

UCLASS&40;&41;  
class UModelingSelectionInteraction :  
    public UObject,  
    public IInputBehaviorSource,  
    public IClickBehaviorTarget,  
    public IHoverBehaviorTarget

Remarks

UModelingSelectionInteraction provides element-level selection behavior (ie mesh triangles/edges/vertices) via the UGeometrySelectionManager. The Interaction doesn't actually know about the meshes or interact with them at all, it simply "operates" the SelectionManager based on user input.

In addition to handling selection/deselection behaviors based on user input, the UModelingSelectionInteraction also creates a Gizmo for the active selection if it is transformable, and forwards gizmo transformations to the SelectionManager.

Currently some desired Selection-related interactions require a slightly convoluted path through the code, because (for example) we want the standard UE editor gizmo to have "click precedence" over our selection click behaviors. However we will get the input event first, so we need to be able to check if the gizmo is hit via a callback function provided by the EdMode owning the ToolsContext this Interaction will be registered in. Similarly we need to be able to filter out hits if a closer visible object is hit, because there is no higher-level Behavior that will do that for us. (This may be improved in future, if more of the existing Editor interaction behaviors are re-implemented as InputBehaviors)

Variables

  Type Name Description
Protected variable EModelingSelectionInteraction_DragMode ActiveDragMode  
Protected variable bool bAddToSelectionEnabled  
Protected variable bool bClearSelectionOnClicked  
Protected variable UProperty TObjectPtr< UInputBehaviorSet > BehaviorSet Set of all behaviors, will be passed up to UInputRouter
Protected variable bool bGizmoUpdatePending  
Protected variable bool bInActiveTransform  
Protected variable bool bToggleSelectionEnabled  
Protected variable TUniqueFunction< bool()> CanChangeSelectionCallback Default change-selection callback always allows selection change
Protected variable UProperty TObjectPtr< USingleClickOrDragInputBehavior > ClickOrDragBehavior Click-to-select behavior, various drag behaviors
Protected variable UProperty TObjectPtr< UDragAlignmentInteraction > DragAlignmentInteraction  
Protected variable UProperty TObjectPtr< UKeyAsModifierInputBehavior > DragAlignmentToggleBehavior  
Protected variable TUniqueFunction< bool(const FInputDeviceRay &)> ExternalHitCaptureCallback  
Protected variable UProperty TObjectPtr< UMouseHoverBehavior > HoverBehavior Mouse hover behavior
Protected variable UE::Geometry::FFrame3d InitialGizmoFrame  
Protected variable FVector3d InitialGizmoScale  
Protected variable FVector4d LastRotateDelta  
Protected variable FVector3d LastScaleDelta  
Protected variable FVector3d LastTranslationDelta  
Protected variable UE::Geometry::FFrame3d LastUpdateGizmoFrame  
Protected variable FVector3d LastUpdateGizmoScale  
Protected variable FDelegateHandle OnSelectionModifiedDelegate  
Public variable FOnBeginTransformInteraction OnTransformBegin  
Public variable FOnEndTransformInteraction OnTransformEnd  
Protected variable UProperty TObjectPtr< UPathSelectionInteraction > PathSelectionInteraction  
Protected variable UProperty TObjectPtr< URectangleMarqueeInteraction > RectangleMarqueeInteraction  
Protected variable UProperty TObjectPtr< UGeometrySelectionManager > SelectionManager  
Protected variable UProperty TObjectPtr< UCombinedTransformGizmo > TransformGizmo  
Protected variable UProperty TObjectPtr< UTransformProxy > TransformProxy  

Functions

  Type Name Description
Public function Virtual void This needs to be called from EdMode tick or rendering, to avoid mouse-interrupt priority issues
Protected function void

ComputeSceneHits ( const FInputDeviceRay& ClickPos,
bool& bHitActiveObjects,
FInputRayHit& ActiveObjectHit,
bool& bHitInactiveObjectFirst,
FInputRayHit& InactiveObjectHit
)

  
Public function Virtual void

DrawHUD ( FCanvas* Canvas,
IToolsContextRenderAPI* RenderAPI
)

  
Public function Const EModelingSelectionInteraction_DragMode Support for drag-style interactions
Public function Const UE::Geometry::FGeometrySelectionUpdateConfig  
Public function UGeometrySelectionManager *  
Public function Virtual void

Initialize ( TObjectPtr< UGeometrySelectionManager > SelectionManager,
TUniqueFunction< bool()> CanChangeSelectionCallbackIn,
TUniqueFunction< bool(const FInputDeviceRay&)> ExternalHitCaptureCallbackIn
)

 Set up the Interaction, creates and registers Behaviors/etc.
Protected function void  
Protected function void  
Protected function void

OnGizmoTransformChanged ( UTransformProxy* Proxy,
FTransform Transform
)

  
Protected function void

OnMarqueeRectangleFinished ( const FCameraRectangle& Rectangle,
bool bCancelled
)

  
Protected function void  
Public function Virtual void  
Public function void  
Public function Virtual void  
Protected function void  
Protected function void  

Overridden from IInputBehaviorSource

  Type Name Description
Public function Virtual Const const UInputBehaviorSet * IInputBehaviorSource API

Overridden from IClickBehaviorTarget

  Type Name Description
Public function Virtual FInputRayHit

IsHitByClick ( const FInputDeviceRay& ClickPos
)

 IClickBehaviorTarget implementation
Public function Virtual void

OnClicked ( const FInputDeviceRay& ClickPos
)

 Notify Target that click ocurred

Overridden from IModifierToggleBehaviorTarget

  Type Name Description
Public function Virtual void

OnUpdateModifierState ( int ModifierID,
bool bIsOn
)

 IModifierToggleBehaviorTarget implementation

Overridden from IHoverBehaviorTarget

  Type Name Description
Public function Virtual FInputRayHit IHoverBehaviorTarget implementation
Public function Virtual void

OnBeginHover ( const FInputDeviceRay& DevicePos
)

 Initialize hover sequence at given position
Public function Virtual void Terminate active hover sequence
Public function Virtual bool

OnUpdateHover ( const FInputDeviceRay& DevicePos
)

 Update active hover sequence with new input position

Typedefs

Name Description
FOnBeginTransformInteraction  
FOnEndTransformInteraction  

Constants

Name Description
AddToSelectionModifier Flags used to identify behavior modifier keys/buttons
ToggleSelectionModifier  

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