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UPreviewMesh

[UPreviewMesh](API\Plugins\ModelingComponents\UPreviewMesh) is a utility object that spawns and owns a transient mesh object in the World.

API > API/Plugins > API/Plugins/ModelingComponents

UPreviewMesh is a utility object that spawns and owns a transient mesh object in the World. This can be used to show live preview geometry during modeling operations. Call CreateInWorld() to set it up, and Disconnect() to shut it down.

Currently implemented via an internal Actor that has a UDynamicMeshComponent root component, with an AABBTree created/updated if FProperty bBuildSpatialDataStructure=true. The Actor is destroyed on Disconnect().

The intention with UPreviewMesh is to provide a higher-level interface than the Component. In future the internal Component may be replaced with another class (eg OctreeDynamicMeshComponent), or automatically swap between the two, etc.

As a result direct access to the Actor/Component, or a non-const FDynamicMesh3, is intentionally not provided. Wrapper functions are provided (or should be added) for necessary Actor/Component parameters. To edit the mesh either a copy is done, or EditMesh()/ApplyChange() must be used. These functions automatically update necessary internal data structures.

   
Name UPreviewMesh
Type class
Header File /Engine/Plugins/Runtime/MeshModelingToolset/Source/ModelingComponents/Public/PreviewMesh.h
Include Path #include "PreviewMesh.h"

Syntax

UCLASS (MinimalAPI, Transient)  
class UPreviewMesh :  
    public UObject ,  
    public IMeshVertexCommandChangeTarget ,  
    public IMeshCommandChangeTarget ,  
    public IMeshReplacementCommandChangeTarget

Inheritance Hierarchy

Implements Interfaces

Derived Classes

Constructors

Name Remarks Include Path Unreal Specifiers

UPreviewMesh()

   PreviewMesh.h  

Destructors

Name Remarks Include Path Unreal Specifiers

virtual ~UPreviewMesh()

   PreviewMesh.h  

Enums

Public

Name Remarks
ERenderUpdateMode Render data update hint (values mirror EDynamicMeshComponentRenderUpdateMode)

Variables

Public

Name Type Remarks Include Path Unreal Specifiers
bBuildSpatialDataStructure bool If true, we build a spatial data structure internally for the preview mesh, which allows for hit-testing PreviewMesh.h  

Functions

Public

Name Remarks Include Path Unreal Specifiers
Calculate tangents for the underlying component. PreviewMesh.h  

void ClearOverrideRenderMaterial()

 Clear the override material for the preview mesh. PreviewMesh.h  

void ClearOverrideSecondaryWireframeRenderMaterial()

 Clear the wireframe override material for the preview mesh. PreviewMesh.h  

void ClearOverrideWireframeRenderMaterial()

 Clear the wireframe override material for the preview mesh. PreviewMesh.h  

void ClearPreview()

 Read access to internal mesh Clear the preview mesh PreviewMesh.h  

void ClearSecondaryRenderMaterial()

 Clear the secondary material for the preview mesh. PreviewMesh.h  

void ClearTriangleColorFunction ( ERenderUpdateMode UpdateMode
)

 Clear the triangle color function for rendering / render data construction PreviewMesh.h  

void CreateInWorld ( UWorld* World,
const FTransform& WithTransform
)

 Construction / destruction Create preview mesh in the World with the given transform PreviewMesh.h  

void DeferredEditMesh ( TFunctionRef< void(FDynamicMesh3&)> EditFunc,
bool bRebuildSpatial
)

 Apply EditFunc to the internal mesh, and update spatial data structure if requested, but do not update/rebuild rendering data structures. PreviewMesh.h  

void DisableSecondaryTriangleBuffers()

 Disable secondary triangle buffers PreviewMesh.h  

void Disconnect()

 Remove and destroy preview mesh PreviewMesh.h  

void EditMesh ( TFunctionRef< void(FDynamicMesh3&)> EditFunc
)

 Apply EditFunc to the internal mesh and update internal data structures as necessary PreviewMesh.h  

void EnableSecondaryTriangleBuffers ( TUniqueFunction< bool(const FDynamicMesh3*, int32)> TriangleFilterFunc
)

 Enable secondary triangle buffers. PreviewMesh.h  

void EnableWireframe ( bool bEnable
)

 Visualization parameters Enable/disable wireframe overlay rendering PreviewMesh.h  

TUniquePtr< FDynamicMesh3 > ExtractPreviewMesh()

   PreviewMesh.h  
Call this after updating the secondary triangle sorting. PreviewMesh.h  

FVector3d FindNearestPoint ( const FVector3d& WorldPoint,
bool bLinearSearch
)

 Find nearest point on current mesh to given WorldPoint Requires that bBuildSpatialDataStructure = true unless bLinearSearch = true PreviewMesh.h  

bool FindRayIntersection ( const FRay3d& WorldRay,
FHitResult& HitOut,
TFunction< bool(int32 Tid)> TriangleFilterF
)

 Find ray intersection with the preview mesh. PreviewMesh.h  
Force rebuild of internal spatial data structure. PreviewMesh.h  

UMaterialInterface * GetActiveMaterial ( int MaterialIndex
) const

   PreviewMesh.h  

AActor * GetActor()

   PreviewMesh.h  

bool GetIsRenderMeshDecompositionEnabled()

   PreviewMesh.h  

UMaterialInterface * GetMaterial ( int MaterialIndex
) const

 Get material from the preview mesh PreviewMesh.h  

void GetMaterials ( TArray< UMaterialInterface* >& OutMaterials
) const

 Get the entire materials array from the preview mesh. Appends to OutMaterials without clearing it. PreviewMesh.h  

const FDynamicMesh3 * GetMesh ()

 Read access to the internal mesh. PreviewMesh.h  

int32 GetNumMaterials()

 Get number of materials in the preview mesh (base materials, i.e., not including override material) PreviewMesh.h  

FSimpleMulticastDelegate & GetOnMeshChanged()

   PreviewMesh.h  

const FDynamicMesh3 * GetPreviewDynamicMesh()

   PreviewMesh.h  

UPrimitiveComponent * GetRootComponent()

   PreviewMesh.h  

UE::Geometry::FDynamicMeshAABBTree3 * GetSpatial ()

 This has to return non-const because of current FDynamicMeshAABBTree3 API, but you should not modify this! PreviewMesh.h  

FTransform GetTransform()

 Get the current transform on the preview mesh PreviewMesh.h  

bool IsVisible()

   PreviewMesh.h  

void NotifyDeferredEditCompleted ( ERenderUpdateMode UpdateMode,
EMeshRenderAttributeFlags ModifiedAttribs,
bool bRebuildSpatial
)

 Notify that a DeferredEditMesh sequence is complete and cause update of rendering data structures. PreviewMesh.h  

void NotifyRegionDeferredEditCompleted ( const TSet< int32 >& Triangles,
EMeshRenderAttributeFlags ModifiedAttribs
)

 Notify that a deferred edit is completed and cause update of rendering data structures for modified Triangles. PreviewMesh.h  

void NotifyRegionDeferredEditCompleted ( const TArray< int32 >& Triangles,
EMeshRenderAttributeFlags ModifiedAttribs
)

 Notify that a deferred edit is completed and cause update of rendering data structures for modified Triangles. PreviewMesh.h  

virtual void ProcessMesh ( TFunctionRef< void(const UE::Geometry::FDynamicMesh3&)> ProcessFunc
) const

 Give external code direct read access to the internal FDynamicMesh3. PreviewMesh.h  

void ReplaceMesh ( FDynamicMesh3&& NewMesh
)

 Replace mesh with new mesh PreviewMesh.h  

void ReplaceMesh ( const FDynamicMesh3& NewMesh
)

 Edit access to internal mesh, and change-tracking/notification Replace mesh with new mesh PreviewMesh.h  

virtual void SetEnableRenderMeshDecomposition ( bool bEnable
)

 Enable automatically-computed decomposition of internal mesh into subregions when rendering (ie inside the Component). PreviewMesh.h  

void SetMaterial ( int MaterialIndex,
UMaterialInterface* Material
)

 Set material on the preview mesh PreviewMesh.h  

void SetMaterial ( UMaterialInterface* Material
)

 Set material on the preview mesh PreviewMesh.h  

void SetMaterials ( const TArray< UMaterialInterface* >& Materials
)

 Set the entire material set on the preview mesh PreviewMesh.h  

void SetOverrideRenderMaterial ( UMaterialInterface* Material
)

 Set an override material for the preview mesh. This material will override all the given materials. PreviewMesh.h  
Set an override secondary wireframe material for the preview mesh. PreviewMesh.h  
Set a override wireframe material for the preview mesh. PreviewMesh.h  

void SetSecondaryBuffersVisibility ( bool bSecondaryVisibility
)

 Show/Hide the secondary triangle buffers. PreviewMesh.h  
Set an secondary material for the preview mesh. PreviewMesh.h  

void SetShadowsEnabled ( bool bEnable
)

 Enable/disable shadow rendering PreviewMesh.h  
Set the tangents mode for the underlying component, if available. PreviewMesh.h  

void SetTransform ( const FTransform& UseTransform
)

 Set the transform on the preview mesh PreviewMesh.h  

void SetTriangleColorFunction ( TFunction< FColor(const FDynamicMesh3*, int)> TriangleColorFunc,
ERenderUpdateMode UpdateMode
)

 Set the triangle color function for rendering / render data construction PreviewMesh.h  

void SetVisible ( bool bVisible
)

 Set visibility state of the preview mesh PreviewMesh.h  

bool TestRayIntersection ( const FRay3d& WorldRay,
TFunction< bool(int32 Tid)> TriangleFilterF
)

 Queries Test for ray intersection with the preview mesh. PreviewMesh.h  
Apply EditFunc to the internal mesh and update internal data structures as necessary. PreviewMesh.h  

void UpdatePreview ( const FDynamicMesh3* Mesh,
ERenderUpdateMode UpdateMode,
EMeshRenderAttributeFlags ModifiedAttribs
)

 Update the internal mesh by copying the given Mesh PreviewMesh.h  

void UpdatePreview ( FDynamicMesh3&& Mesh,
ERenderUpdateMode UpdateMode,
EMeshRenderAttributeFlags ModifiedAttribs
)

 Update the internal mesh by moving in the given Mesh PreviewMesh.h  

Overridden from IMeshVertexCommandChangeTarget

Name Remarks Include Path Unreal Specifiers

virtual void ApplyChange ( const FMeshVertexChange* Change,
bool bRevert
)

 Apply/Revert a vertex deformation change to the internal mesh (implements IMeshVertexCommandChangeTarget) PreviewMesh.h  

Overridden from IMeshCommandChangeTarget

Name Remarks Include Path Unreal Specifiers

virtual void ApplyChange ( const FMeshChange* Change,
bool bRevert
)

 Apply/Revert a general mesh change to the internal mesh (implements IMeshCommandChangeTarget) PreviewMesh.h  

Overridden from IMeshReplacementCommandChangeTarget

Name Remarks Include Path Unreal Specifiers

virtual void ApplyChange ( const FMeshReplacementChange* Change,
bool bRevert
)

 Apply/Revert a general mesh change to the internal mesh (implements IMeshReplacementCommandChangeTarget) PreviewMesh.h  

Protected

Name Remarks Include Path Unreal Specifiers

void NotifyWorldPathTracedOutputInvalidated()

 This function is called internally on some changes, to let the path tracer know that this mesha/actor has been modified in a way that will require invalidating the current path tracing result PreviewMesh.h  

void UpdateRenderMeshDecomposition()

 Update chunk decomposition PreviewMesh.h  

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