UMeshOpPreviewWithBackgroundCompute | Unreal Engine 5.2 Documentation

API > API/Plugins > API/Plugins/ModelingComponents

Inheritance Hierarchy

UObjectBase
UObjectBaseUtility
UObject
UMeshOpPreviewWithBackgroundCompute

References


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

Syntax

UCLASS&40;Transient&41;  
class UMeshOpPreviewWithBackgroundCompute : public UObject

Remarks

UMeshOpPreviewWithBackgroundCompute is an infrastructure object that implements a common UI pattern in interactive 3D tools, where we want to run an expensive computation on a mesh that is based on user-specified parameters, and show a preview of the result. The expensive computation (a MeshOperator) must run in a background thread so as to not block the UI. If the user changes parameters while the Operator is running, it should be canceled and restarted. When it completes, the Preview will be updated. When the user is happy, the current Mesh is returned to the owner of this object.

The MeshOperators are provided by the owner via a IDynamicMeshOperatorFactory implementation. The owner must also Tick() this object regularly to allow the Preview to update when the background computations complete.

If an InProgress Material is set (via ConfigureMaterials) then when a background computation is active, this material will be used to draw the previous Preview result, to give the user a visual indication that work is happening.

Variables

Type	Name	Description
TUniquePtr< FBackgroundDynamicMeshComputeSource >	BackgroundCompute	This object manages the background computes
bool	bAllowDirtyResultUpdates	When true, the preview mesh is allowed to be temporarily updated using results that we know are dirty (i.e., the preview was invalidated, but a result became available before the operation was restarted, so we can at least show that while we wait for the new result).
bool	bMeshInitialized
bool	bMeshTopologyIsConstant	Used for partial/fast updates of the preview mesh render proxy.
bool	bResultValid	State flag, if true then we have valid result
bool	bVisible
EMeshRenderAttributeFlags	ChangingAttributeFlags
UE::Geometry::EBackgroundComputeTaskStatus	LastComputeStatus	Stored status of last compute, mainly so that we know when we should show the "busy" material.
FOnMeshUpdated	OnMeshUpdated	This delegate is broadcast whenever the embedded preview mesh is updated
FOnOpCompleted	OnOpCompleted
TObjectPtr< UMaterialInterface >	OverrideMaterial	Override material to forward to PreviewMesh if set
TObjectPtr< UPreviewMesh >	PreviewMesh	Preview of MeshOperator result
TWeakObjectPtr< UWorld >	PreviewWorld
TObjectPtr< UMaterialInterface >	SecondaryMaterial	Secondary render material to forward to PreviewMesh if set
float	SecondsBeforeWorkingMaterial
TArray< TObjectPtr< UMaterialInterface > >	StandardMaterials	Input set of materials to assign to PreviewMesh
double	ValidResultComputeTimeSeconds
TObjectPtr< UMaterialInterface >	WorkingMaterial	If non-null, this material is swapped in when a background compute is active

Functions

Type	Name	Description
void	Cancel ()	Terminate any active computation without returning anything. Destroys the preview mesh.
void	CancelCompute ()	Cancel the active computation without returning anything. Doesn't destroy the mesh.
void	ChangeOpFactory ( UE::Geometry::IDynamicMeshOperatorFactory* OpGenerator )	Stops any running computes and swaps in a different op generator.
void	ClearOpFactory ()
void	ConfigureMaterials ( TArray< UMaterialInterface* > StandardMaterials, UMaterialInterface* InProgressMaterial, UMaterialInterface* SecondaryMaterial )	Configure the Standard and In-Progress materials
void	ConfigureMaterials ( UMaterialInterface* StandardMaterial, UMaterialInterface* InProgressMaterial )	Optional configuration Configure the Standard and In-Progress materials
void	ConfigurePreviewMaterials ( UMaterialInterface* InProgressMaterial, UMaterialInterface* SecondaryMaterial )	Configure the In-Progress and Secondary Materials
void	DisablePreviewMaterials ()	Disable the In Progress and Secondary Materials
bool	GetCurrentResultCopy ( FDynamicMesh3& MeshOut, bool bOnlyIfValid )	Read back a copy of current preview mesh.
double	GetValidResultComputeTime ()
UWorld *	GetWorld ()
bool	HaveEmptyResult ()
bool	HaveValidNonEmptyResult ()
bool	HaveValidResult ()
void	InvalidateResult ()	Control flow Request that the current computation be canceled and a new one started
bool	IsUsingWorkingMaterial ()
bool	ProcessCurrentMesh ( TFunctionRef< void(const UE::Geometry::FDynamicMesh3&)> ProcessFunc, bool bOnlyIfValid )	Allow an external function to safely access the PreviewMesh's mesh
void	SetIsMeshTopologyConstant ( bool bOn, EMeshRenderAttributeFlags ChangingAttributes )	If set to true, then it will be assumed that the mesh topology (i.e. triangle/edge connectivity) remains constant, which will allow updates after the first one to modify existing render proxy buffers rather than creating entirely new ones.
void	Setup ( UWorld* InWorld )
void	Setup ( UWorld* InWorld, UE::Geometry::IDynamicMeshOperatorFactory* OpGenerator )	Required calls to setup/update/shutdown this object
void	SetVisibility ( bool bVisible )	Set the visibility of the Preview mesh
void	SetWorkingMaterialDelay ( float TimeInSeconds )	Set time that Preview will wait before showing working material
FDynamicMeshOpResult	Shutdown ()	Terminate any active computation and return the current Preview Mesh/Transform
void	Tick ( float DeltaTime )	Tick the background computation and Preview update.
void	UpdateResults ()	Update the PreviewMesh if a new result is available from BackgroundCompute

Typedefs

Name	Description
FOnMeshUpdated	Change notification
FOnOpCompleted

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