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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

Inheritance Hierarchy

References

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

Syntax

UCLASS&40;Transient&41;  
class UPreviewMesh :  
    public UObject,  
    public IMeshVertexCommandChangeTarget,  
    public IMeshCommandChangeTarget,  
    public IMeshReplacementCommandChangeTarget

Remarks

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.

Variables

  Type Name Description
Public variable UProperty bool bBuildSpatialDataStructure If true, we build a spatial data structure internally for the preview mesh, which allows for hit-testing
Protected variable bool bDecompositionEnabled If true, mesh will be chunked into multiple render buffers inside the DynamicMeshComponent
Protected variable UProperty TObjectPtr< UDynamicMeshComponent > DynamicMeshComponent This component is set as the root component of TemporaryParentActor
Protected variable UE::Geometry::FDynamicMeshAABBTree3 MeshAABBTree Spatial data structure that is initialized if bBuildSpatialDataStructure = true when UpdatePreview() is called
Protected variable APreviewMeshActor * TemporaryParentActor The temporary actor we create internally to own the preview mesh component

Constructors

  Type Name Description
Public function    

Destructors

  Type Name Description
Public function Virtual    

Functions

  Type Name Description
Public function bool Calculate tangents for the underlying component.
Public function void Clear the override material for the preview mesh.
Public function void Read access to internal mesh Clear the preview mesh
Public function void Clear the secondary material for the preview mesh.
Public function void Clear the triangle color function for rendering / render data construction
Public function void

CreateInWorld ( UWorld* World,
const FTransform& WithTransform
)

 Construction / destruction Create preview mesh in the World with the given transform
Public function 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.
Public function void Disable secondary triangle buffers
Public function void Remove and destroy preview mesh
Public function void

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

 Apply EditFunc to the internal mesh and update internal data structures as necessary
Public function void

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

 Enable secondary triangle buffers.
Public function void

EnableWireframe ( bool bEnable
)

 Visualization parameters Enable/disable wireframe overlay rendering
Public function Const TUniquePtr< FDynamicMesh3 >  
Public function void Call this after updating the secondary triangle sorting.
Public function FVector3d

FindNearestPoint ( const FVector3d& WorldPoint,
bool bLinearSearch
)

 Find nearest point on current mesh to given WorldPoint Requires that bBuildSpatialDataStructure = true unless bLinearSearch = true
Public function bool

FindRayIntersection ( const FRay3d& WorldRay,
FHitResult& HitOut
)

 Find ray intersection with the preview mesh.
Public function void Force rebuild of internal spatial data structure.
Public function Const UMaterialInterface *

GetActiveMaterial ( int MaterialIndex
)

  
Public function Const AActor *  
Public function Const bool  
Public function Const UMaterialInterface *

GetMaterial ( int MaterialIndex
)

 Get material from the preview mesh
Public function Const void

GetMaterials ( TArray< UMaterialInterface* >& OutMaterials
)

 Get the entire materials array from the preview mesh. Appends to OutMaterials without clearing it.
Public function Const const FDynamicMesh3 *

GetMesh ()

 Read access to the internal mesh.
Public function Const int32 Get number of materials in the preview mesh (base materials, i.e., not including override material)
Public function FSimpleMulticastDelegate &  
Public function Const const FDynamicMesh3 *  
Public function UPrimitiveComponent *  
Public function UE::Geometry::FDynamicMeshAABBTree3 * This has to return non-const because of current FDynamicMeshAABBTree3 API, but you should not modify this!
Public function Const FTransform Get the current transform on the preview mesh
Public function Const bool  
Public function void

NotifyDeferredEditCompleted ( ERenderUpdateMode UpdateMode,
EMeshRenderAttributeFlags ModifiedAttribs,
bool bRebuildSpatial
)

 Notify that a DeferredEditMesh sequence is complete and cause update of rendering data structures.
Public function 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.
Public function 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.
Protected function void 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
Public function Virtual Const void

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

 Give external code direct read access to the internal FDynamicMesh3.
Public function void

ReplaceMesh ( FDynamicMesh3&& NewMesh
)

 Replace mesh with new mesh
Public function void

ReplaceMesh ( const FDynamicMesh3& NewMesh
)

 Edit access to internal mesh, and change-tracking/notification Replace mesh with new mesh
Public function Virtual void Enable automatically-computed decomposition of internal mesh into subregions when rendering (ie inside the Component).
Public function void

SetMaterial ( int MaterialIndex,
UMaterialInterface* Material
)

 Set material on the preview mesh
Public function void Set material on the preview mesh
Public function void

SetMaterials ( const TArray< UMaterialInterface* >& Materials
)

 Set the entire material set on the preview mesh
Public function void Set an override material for the preview mesh. This material will override all the given materials.
Public function void

SetSecondaryBuffersVisibility ( bool bSecondaryVisibility
)

 Show/Hide the secondary triangle buffers.
Public function void Set an secondary material for the preview mesh.
Public function void

SetShadowsEnabled ( bool bEnable
)

 Enable/disable shadow rendering
Public function void

SetTangentsMode ( EDynamicMeshComponentTangentsMode TangentsType
)

 Set the tangents mode for the underlying component, if available.
Public function void

SetTransform ( const FTransform& UseTransform
)

 Set the transform on the preview mesh
Public function void

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

 Set the triangle color function for rendering / render data construction
Public function void

SetVisible ( bool bVisible
)

 Set visibility state of the preview mesh
Public function bool

TestRayIntersection ( const FRay3d& WorldRay
)

 Queries Test for ray intersection with the preview mesh.
Public function TUniquePtr< FMeshChange > Apply EditFunc to the internal mesh and update internal data structures as necessary.
Public function void

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

 Update the internal mesh by copying the given Mesh
Public function void

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

 Update the internal mesh by moving in the given Mesh
Protected function void Update chunk decomposition

Overridden from IMeshVertexCommandChangeTarget

  Type Name Description
Public function Virtual void

ApplyChange ( const FMeshVertexChange* Change,
bool bRevert
)

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

Overridden from IMeshCommandChangeTarget

  Type Name Description
Public function Virtual void

ApplyChange ( const FMeshChange* Change,
bool bRevert
)

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

Overridden from IMeshReplacementCommandChangeTarget

  Type Name Description
Public function Virtual void

ApplyChange ( const FMeshReplacementChange* Change,
bool bRevert
)

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

Enums

  Type Name Description
Public enum ERenderUpdateMode Render data update hint (values mirror EDynamicMeshComponentRenderUpdateMode)  

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