Can't find any content

Error loading documents tree: Nothing found

  1. Epic GamesDeveloper
  3. UGeometrySelectionManager

UGeometrySelectionManager

[UGeometrySelectionManager](API\Plugins\ModelingComponents\Selection\UGeometrySelectionManager) provides the infrastructure for "Element Selection", ie geometric sub-elements of some geometry object like a Triangle Mesh.

API > API/Plugins > API/Plugins/ModelingComponents > API/Plugins/ModelingComponents/Selection

Inheritance Hierarchy

References

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

Syntax

UCLASS ()  
class UGeometrySelectionManager : public UObject

Remarks

UGeometrySelectionManager provides the infrastructure for "Element Selection", ie geometric sub-elements of some geometry object like a Triangle Mesh. The Manager is designed to work with a relatively vague concept of "element", so it doesn't explicitly reference triangles/etc, and the selectable-elements and how-elements-are-selected concepts are provided by abstract-interfaces that allow various implememtations.

The "Geometry Objects", eg like a DynamicMeshComponent, Gameplay Volume, etc, are referred to as "Active Targets" in the Manager. External code provides and updates the set of Active Targets, eg for example tracking the active Actor Selection in the Editor.

For a given Target, a tuple (Selector, Selection, SelectionEditor) is created and maintained. The FGeometrySelection is ultimately a basic list of integers and does not have any knowledge of what it is a selection of, and is not intended to be directly edited. Instead the SelectionEditor provides that functionality. This separation allows "selection editing" to be customized, eg to enforce invariants or constraints that might apply to certain kinds of selections.

The IGeometrySelector provides the core implementation of what "selection" means for a given Target, eg like a mesh Component, or mesh object like a UDynamicMesh. The Selector is created by a registered Factory, allowing client code to provide custom implementations for different Target Types. Updates to the Selection are done via the Selector, as well as queries about (eg) renderable selection geometry. 3D Transforms are also applied via the Selector, as only it has the knowledge about what can be transformed and how it can be applied.

The GeometrySelectionManager provides high-level interfaces for this system, for example external code (eg such as something that creates a Gizmo for the active selection) only needs to interact with SelectionManager, calling functions like BeginTransformation() / UpdateTransformation() / EndTransformation(). The SelectionManager also handles Transactions/FChanges for the active Targets and Selections.

Variables

  Type Name Description
Protected variable FGeometrySelection ActivePreviewSelection  
Protected variable TMap< FGeometryIdentifier, TSharedPtr< FGeometrySelectionTarget > > ActiveTargetMap Map from external Identifiers to active Selection Targets
Protected variable TArray< TSharedPtr< FGeometrySelectionTarget > > ActiveTargetReferences Set of active Selection Targets updated by SynchronizeActiveTargets / etc.
Protected variable UE::Geometry::FGeometrySelectionDelta ActiveTrackedDelta  
Protected variable FGeometrySelection ActiveTrackedSelection  
Protected variable FGeometrySelectionUpdateConfig ActiveTrackedUpdateConfig  
Protected variable TArray< IGeometrySelectionTransformer * > ActiveTransformations Transformations Set of existing transformer objects, collected from active IGeometrySelector::InitializeTransformation().
Protected variable bool bInTrackedSelectionChange Support for complex selection changes that are driven externally
Protected variable bool bSelectionModifiedDuringTrackedChange  
Protected variable FGeometrySelectionElements CachedSelectedPreviewRenderElements  
Protected variable TArray< FGeometrySelectionElements > CachedSelectionRenderElements  
Protected variable FGeometrySelectionElements CachedUnselectedPreviewRenderElements  
Protected variable TArray< TUniquePtr< IGeometrySelectorFactory > > Factories Set of registered IGeometrySelector factories
Protected variable UProperty FMeshElementSelectionParams HoverOverSelectedParams  
Protected variable UProperty FMeshElementSelectionParams HoverOverUnselectedParams  
Protected variable UE::Geometry::FGeometrySelectionDelta InitialTrackedDelta  
Protected variable EMeshTopologyMode MeshTopologyMode  
Public variable FModelingSelectionInteraction_SelectionModified OnSelectionModified OnSelectionModified is broadcast if the selection is modified via the above functions.
Protected variable UProperty TObjectPtr< UPreviewGeometry > PreviewGeometry  
Protected variable FGeometrySelection SelectedActivePreviewSelection  
Protected variable UProperty FMeshElementSelectionParams SelectedParams  
Protected variable UProperty TObjectPtr< UGeometrySelectionEditCommandArguments > SelectionArguments This is set to current selection during CanExecuteSelectionCommand/ExecuteSelectionCommand, to keep the UObject alive Not expected to be used outside that context
Protected variable EGeometryElementType SelectionElementType  
Protected variable TMap< FGeometryIdentifier, TSharedPtr< FGeometrySelectionTarget > > TargetCache Support for cached FGeometrySelectionTarget / IGeometrySelectors.
Protected variable UProperty TObjectPtr< UInteractiveToolsContext > ToolsContext  
Protected variable IToolsContextTransactionsAPI * TransactionsAPI  
Protected variable TArray< FGeometryIdentifier > UnlockedTargets  
Protected variable FGeometrySelection UnselectedActivePreviewSelection  
Protected variable UProperty FMeshElementSelectionParams UnselectedParams  

Functions

  Type Name Description
Public function Virtual void Update the tracked selection change via a single Raycast, using the active UpdateConfig mode passed to BeginTrackedSelectionChange
Public function bool Add a target to the active target set, if a valid IGeometrySelectorFactory can be found
Public function Virtual void Undo/Redo
Public function Virtual bool

BeginTrackedSelectionChange ( FGeometrySelectionUpdateConfig UpdateConfig,
bool bClearOnBegin
)

 Begin a tracked selection change.
Public function Virtual bool Begin a transformation of element selections in active Targets.
Public function Virtual Const bool Support for more complex selection changes that might (eg) occur over multiple frames, or be computed externally.
Public function bool Command Execution
Protected function void  
Public function void Empty the active selection target set
Public function Virtual void

ClearSelection ( bool bSaveSelectionBeforeClear
)

 Selection Updates Clear any active element selections.
Public function Virtual void Resets the active preview selection and invalidates its associated cached render elements.
Protected function Const void Calls the CreateOrUpdate function for Triangle, Line, and Point sets to build sets for PreviewGeometry
Public function Virtual void Debugging stuff Print information about the active selection using UE_LOG
Public function Virtual void Visualize the active selection using PDI drawing
Public function Virtual void Discard the saved selection, if there is one.
Public function void Disconnect and cleanup for PreviewGeometry object.
Public function Virtual void Close an active tracked selection change.
Public function Virtual void End the current active transformation, and emit changes/transactions
Public function void Execute the selection command for all the current selections
Public function Virtual Const void

GetActiveSelectionInfo ( EGeometryTopologyType& TopologyTypeOut,
EGeometryElementType& ElementTypeOut,
int& NumTargetsOut,
bool& bIsEmpty
)

 Get available information about the active selection/state
Public function Const bool  
Public function Const bool  
Protected function TSharedPtr< FGeometrySelectionTarget >  
Protected function Const UE::Geometry::FGeometrySelectionHitQueryConfig  
Protected function Const TArray< FGeometryIdentifier >  
Public function Virtual Const EMeshTopologyMode  
Public function Virtual Const bool  
Public function Virtual Const EGeometryElementType  
Public function Virtual Const bool

GetSelectionForComponent ( UPrimitiveComponent* Component,
FGeometrySelection& SelectionOut
)

 Get the active element selection for the given Component, if it exists
Public function Virtual Const EGeometryTopologyType  
Public function Virtual Const void  
Public function Virtual Const void  
Public function Const UInteractiveToolsContext *  
Public function Const IToolsContextTransactionsAPI *  
Public function Const bool Target Management / Queries TODO: be able to update active target set w/o losing current selections?
Public function Virtual Const bool  
Public function Virtual bool  
Public function Virtual Const bool Selection queries
Public function Virtual Const bool

HasSelectionForComponent ( UPrimitiveComponent* Component
)

  
Public function Virtual void

Initialize ( UInteractiveToolsContext* ToolsContextIn,
IToolsContextTransactionsAPI* TransactionsAPIIn
)

 Setup/Teardown
Public function Virtual Const bool  
Public function Virtual Const bool  
Public function void

MarkRenderCachesDirty ( bool bMarkSelectableDirty
)

 Invalidates all cached selection elements by default.
Protected function void  
Protected function void Apply ProcessFunc to active selections via handles, perhaps should be public?
Public function Virtual bool

RayHitTest ( const FRay3d& WorldRay,
FInputRayHit& HitResultOut
)

 Test if a World-space ray "hits" the current active target set, which can be used to (eg) determine if a higher-level user interaction for selection should "Capture" the click
Protected function void  
Public function Virtual void  
Public function Const void

RemoveSets ( const TArrayView< FString >& SetIdentifiers
)

 Removes Triangle, Line, and Point sets with the given SetIdentifier prefix Full Identifier strings are in the format: SetIdentifier_Triangles, SetIdentifier_Lines, and SetIdentifier_Points
Protected function void  
Public function Virtual bool Attempt to restore (and then discard) the most recent saved selection.
Public function Virtual void  
Protected function Virtual void Save the active selection.
Public function void

SetCurrentTargetsLockState ( bool bLocked
)

  
Public function Virtual void

SetMeshSelectionTypeAndMode ( EGeometryElementType NewElementType,
EMeshTopologyMode NewSelectionMode,
bool bConvertSelection
)

 Switch the selection mode and type, optionally converting any existing selection to the new type and mode.
Public function Virtual void  
Protected function void  
Public function void

SetSelectionColors ( FLinearColor UnselectedCol,
FLinearColor HoverOverSelectedCol,
FLinearColor HoverOverUnselectedCol,
FLinearColor GeometrySelectedCol
)

 Set the colors to be used during mesh element selection for: Unselected elements, Hover over selection, Hover over non-selection, and Selected elements
Public function Virtual void  
Protected function void  
Public function Virtual bool

SetSelectionForComponent ( UPrimitiveComponent* Component,
const FGeometrySelection& NewSelection
)

 Directly set the current Selection for the specified Component to NewSelection.
Protected function void

SetTargetLockStateOnUndoRedo ( FGeometryIdentifier TargetIdentifier,
bool bLocked
)

  
Protected function void  
Public function Virtual void  
Protected function void

SleepOrShutdownTarget ( TSharedPtr< FGeometrySelectionTarget > Target,
bool bForceShutdown
)

  
Public function void

SynchronizeActiveTargets ( const TArray< FGeometryIdentifier >& DesiredActiveSet,
TFunctionRef< void()> WillChangeActiveTargetsCallback
)

 Update the current active target set based on DesiredActiveSet, assuming that a valid IGeometrySelectorFactory can be found for each identifier.
Public function Virtual bool Hover/Preview support
Protected function void  
Public function Virtual void

UpdateSelectionViaConvex ( const FConvexVolume& ConvexVolume,
const FGeometrySelectionUpdateConfig& UpdateConfig,
FGeometrySelectionUpdateResult& ResultOut
)

 Use the given ConvexVolume to update the active element selection based on UpdateConfig.
Public function Virtual void Use the given WorldRay to update the active element selection based on UpdateConfig.
Public function Virtual void

UpdateTransformation ( TFunctionRef< FVector3d(int32 VertexID, const FVector3d&, const FTransform&)> PositionTransformFun...
)

 Update the active transformations with the given PositionTransformFunc.
Public function Const bool Attempt to validate the current selection state; can be called to detect if e.g. selected objects have been deleted from under the selection manager.

Classes

  Type Name Description
Protected struct FGeometrySelectionTarget FGeometrySelectionTarget is the set of information tracked for a given "Active Target", which is (eg) a Mesh Component or other external object that "owns" selectable Geometry.  

Enums

  Type Name Description
Public enum EMeshTopologyMode Configuration EMeshTopologyMode determines what level of mesh element will be selected  

Typedefs

Name Description
EGeometryElementType  
EGeometryTopologyType  
FGeometrySelection  
FGeometrySelectionBounds  
FGeometrySelectionEditor  
FGeometrySelectionElements  
FGeometrySelectionUpdateConfig  
FGeometrySelectionUpdateResult  
FModelingSelectionInteraction_SelectionModified  

Constants

Name Description
HoverOverSelectedSetIds  
HoverOverUnselectedSetIds  
SelectedSetIds  
UnselectedSetIds  

Ask questions and help your peers Developer Forums

Write your own tutorials or read those from others Learning Library

On this page