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  3. UDynamicMeshComponent

UDynamicMeshComponent

[UDynamicMeshComponent](API\Runtime\GeometryFramework\Components\UDynamicMeshComponent) is a mesh component similar to [UProceduralMeshComponent](API\Plugins\ProceduralMeshComponent\UProceduralMeshComponent), except it bases the renderable geometry off an internal [UDynamicMesh](API\Runtime\GeometryFramework\UDynamicMesh) instance (which encapsulates a FDynamicMesh3).

API > API/Runtime > API/Runtime/GeometryFramework > API/Runtime/GeometryFramework/Components

Inheritance Hierarchy

References

   
Module GeometryFramework
Header /Engine/Source/Runtime/GeometryFramework/Public/Components/DynamicMeshComponent.h
Include #include "Components/DynamicMeshComponent.h"

Syntax

class UDynamicMeshComponent :  
    public UBaseDynamicMeshComponent,  
    public IInterface_CollisionDataProvider

Remarks

UDynamicMeshComponent is a mesh component similar to UProceduralMeshComponent, except it bases the renderable geometry off an internal UDynamicMesh instance (which encapsulates a FDynamicMesh3).

There is extensive support for partial updates to render buffers, customizing colors, internally decomposing the mesh into separate chunks for more efficient render updates, and support for attaching a 'Postprocessor' to generate a render mesh on-the-fly See comment sections below for details.

Variables

  Type Name Description
Protected variable FKAggregateGeom AggGeom Internals for managing collision representation and setupSimplified collision representation for the mesh component
Protected variable TArray< TObjectPtr< UBodySetup > > AsyncBodySetupQueue Queue for async body setups that are being cooked
Protected variable UE::Geometry::FMeshTangentsf AutoCalculatedTangents Set of per-triangle-vertex tangents computed for the current mesh.
Protected variable bool bAutoCalculatedTangentsValid True if AutoCalculatedTangents has been computed for current mesh
Protected variable bool bCollisionUpdatePending  
Public variable bool bDeferCollisionUpdates If true, updates to the mesh will not result in immediate collision regeneration.
Public variable bool bEnableComplexCollision If true, current mesh will be used as Complex Collision source mesh.
Protected variable bool bInvalidateProxyOnChange If false, we don't completely invalidate the RenderProxy when ApplyChange() is called (assumption is it will be handled elsewhere)
Protected variable bool bProxyValid If the render proxy is invalidated (eg by MarkRenderStateDirty()), it will be destroyed at the end of the frame, but the base SceneProxy pointer is not nulled out immediately.
Protected variable bool bProxyVerifyUsedMaterials If true, the render proxy will verify that the mesh batch materials match the contents from the component GetUsedMaterials().
Protected variable bool bTransientDeferCollisionUpdates  
Public variable bool bUseAsyncCooking Controls whether the physics cooking should be done off the game thread.
Public variable TEnumAsByte< enum ECollisionTraceFlag > CollisionType Type of Collision Geometry to use for this Mesh
Protected variable TUniquePtr< FMeshRenderDecomposition > Decomposition  
Protected variable UE::Geometry::FAxisAlignedBox3d LocalBounds Standard Component internals, for computing bounds and managing the SceneProxyCurrent local-space bounding box of Mesh
Protected variable TObjectPtr< UBodySetup > MeshBodySetup  
Protected variable TObjectPtr< UDynamicMesh > MeshObject Internal FDynamicMesh is stored inside a UDynamicMesh container, which allows it to be used from BP, shared with other UObjects, and so on
Protected variable FDelegateHandle MeshObjectChangedHandle Handle for OnMeshObjectChanged which is registered with MeshObject::OnMeshChanged delegate
Public variable FComponentChildrenChangedDelegate OnChildAttachmentModified The OnChildAttached() and OnChildDetached() implementations (from USceneComponent API) broadcast this delegate.
Public variable FSimpleMulticastDelegate OnMeshChanged This delegate fires when the mesh has been changed
Public variable FMeshVerticesModified OnMeshVerticesChanged  
Protected variable TUniquePtr< FDynamicMesh3 > RenderMesh  
Protected variable TUniquePtr< IRenderMeshPostProcessor > RenderMeshPostProcessor  
Protected variable TUniqueFunction< bool(const FDynamicMesh3 *, int32)> SecondaryTriFilterFunc  
Protected variable EDynamicMeshComponentTangentsMode TangentsType Tangent source defines whether we use the provided tangents on the Dynamic Mesh, autogenerate tangents, or do not use tangents
Protected variable TUniqueFunction< FColor(const FDynamicMesh3 *, int)> TriangleColorFunc If this function is set, we will use these colors instead of vertex colors
Protected variable TUniqueFunction< void(FVector4f &)> VertexColorMappingFunc If this function is set, DynamicMesh Attribute Color Overlay colors will be passed through this function before sending to render buffers

Constructors

  Type Name Description
Public function  

UDynamicMeshComponent ( const FObjectInitializer& ObjectInitializer
)

  

Functions

  Type Name Description
Public function Virtual void

ClearSimpleCollisionShapes ( bool bUpdateCollision
)

 Clear the simple collision shapes associated with this mesh component
Public function Virtual void

ClearTriangleColorFunction ( EDynamicMeshComponentRenderUpdateMode UpdateMode
)

 Clear an active triangle color function if one exists, and update the mesh
Public function Virtual void

ClearVertexColorRemappingFunction ( EDynamicMeshComponentRenderUpdateMode UpdateMode
)

 Clear an active VertexColor Remapping function if one exists, and update the mesh
Public function void

ConfigureMaterialSet ( const TArray< UMaterialInterface* >& NewMaterialSet
)

 Material Set API. DynamicMeshComponent supports changing the Material Set dynamically, even at Runtime.
Protected function Virtual UBodySetup *  
Public function Virtual void Disable secondary triangle buffers. This invalidates the SceneProxy.
Public function Virtual void

EditMesh ( TFunctionRef< void(UE::Geometry::FDynamicMesh3&)> EditFunc,
EDynamicMeshComponentRenderUpdateMode UpdateMode
)

 Allow external code to to edit the internal mesh.
Public function void Physics APIs calls SetComplexAsSimpleCollisionEnabled(true, true)
Public function Virtual void

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

 Support for Secondary triangle index buffers.
Public function void Call this instead of NotifyMeshUpdated() if you have only updated the vertex colors (or triangle color function).
Public function void

FastNotifyPositionsUpdated ( bool bNormals,
bool bColors,
bool bUVs
)

 Call this instead of NotifyMeshUpdated() if you have only updated the vertex positions (and possibly some attributes).
Public function void Call this instead of NotifyMeshUpdated() if you have only updated secondary triangle sorting.
Public function void

FastNotifyTriangleVerticesUpdated ( const TArray< int32 >& Triangles,
EMeshRenderAttributeFlags UpdatedAttributes
)

 This function updates vertex positions/attributes of existing SceneProxy render buffers if possible, for the given triangles.
Public function void

FastNotifyTriangleVerticesUpdated ( const TSet< int32 >& Triangles,
EMeshRenderAttributeFlags UpdatedAttributes
)

 This function updates vertex positions/attributes of existing SceneProxy render buffers if possible, for the given triangles.
Public function void

FastNotifyTriangleVerticesUpdated_ApplyPrecompute ( const TArray< int32 >& Triangles,
EMeshRenderAttributeFlags UpdatedAttributes,
TFuture< bool >& Precompute,
const TArray< int32 >& UpdateSets,
const UE::Geometry::FAxisAlignedBox3d& UpdateSetBounds
)

 This function updates vertex positions/attributes of existing SceneProxy render buffers if possible, for the given triangles.
Public function TFuture< bool >

FastNotifyTriangleVerticesUpdated_TryPrecompute ( const TArray< int32 >& Triangles,
TArray< int32 >& UpdateSetsOut,
UE::Geometry::FAxisAlignedBox3d& BoundsOut
)

 If a Decomposition is set on this Component, and everything is currently valid (proxy/etc), precompute the set of buffers that will be modified, as well as the bounds of the modified region.
Public function void Call this instead of NotifyMeshUpdated() if you have only updated the vertex uvs.
Public function void

FastNotifyVertexAttributesUpdated ( bool bNormals,
bool bColors,
bool bUVs
)

 Call this instead of NotifyMeshUpdated() if you have only updated the vertex attributes (but not positions).
Public function void

FastNotifyVertexAttributesUpdated ( EMeshRenderAttributeFlags UpdatedAttributes
)

 Call this instead of NotifyMeshUpdated() if you have only updated the vertex positions/attributes This function will update the existing RenderProxy buffers if possible, rather than create new ones.
Protected function Virtual void

FinishPhysicsAsyncCook ( bool bSuccess,
UBodySetup* FinishedBodySetup
)

 Once async physics cook is done, create needed state
Public function const UE::Geometry::FMeshTangentsf *  
Public function Virtual Const const UBodySetup *  
Protected function FDynamicMeshSceneProxy *  
Protected function Const FColor

GetGroupColor ( const FDynamicMesh3* Mesh,
int TriangleID
)

 This function is passed via lambda to the RenderProxy when BaseDynamicMeshComponent::ColorMode == Polygroups
Public function Const bool  
Public function Virtual FDynamicMesh3 * The SceneProxy should call these functions to get the post-processed RenderMesh.
Public function Virtual Const const FDynamicMesh3 * The SceneProxy should call these functions to get the post-processed RenderMesh.
Public function Const const FKAggregateGeom &  
Public function Const EDynamicMeshComponentTangentsMode  
Protected function FColor

GetTriangleColor ( const FDynamicMesh3* Mesh,
int TriangleID
)

 This function is passed via lambda to the RenderProxy to be able to access TriangleColorFunc
Public function Virtual bool  
Public function Virtual bool  
Public function Virtual void This function marks the auto tangents as dirty, they will be recomputed before they are used again
Protected function Virtual void  
Public function Virtual void RenderBuffer Update Blueprint API.
Public function Virtual void

NotifyMeshVertexAttributesModified ( bool bPositions,
bool bNormals,
bool bUVs,
bool bColors
)

 Notify the Component that vertex attribute values of it's DynamicMesh have been modified externally.
Protected function void

OnMeshObjectChanged ( UDynamicMesh* ChangedMeshObject,
FDynamicMeshChangeInfo ChangeInfo
)

 Called whenever internal MeshObject is modified, fires OnMeshChanged and OnMeshVerticesChanged above
Protected function Virtual void  
Protected function void

RemapVertexColor ( FVector4f& VertexColorInOut
)

 This function is passed via lambda to the RenderProxy to be able to access VertexColorMappingFunc
Protected function void Fully invalidate all rendering data for this Component.
Protected function Virtual void

SetBodySetup ( UBodySetup* NewSetup
)

  
Public function void

SetComplexAsSimpleCollisionEnabled ( bool bEnabled,
bool bImmediateUpdate
)

 If bEnabled=true, sets bEnableComplexCollision=true and CollisionType=CTF_UseComplexAsSimple If bEnabled=true, sets bEnableComplexCollision=false and CollisionType=CTF_UseDefault
Public function void

SetDeferredCollisionUpdatesEnabled ( bool bEnabled,
bool bImmediateUpdate
)

 Set value of bDeferCollisionUpdates, when enabled, collision is not automatically recomputed each time the mesh changes.
Public function void Replace the current UDynamicMesh with a new one, and transfer ownership of NewMesh to this Component.
Public function Virtual void Support for a Render Decomposition, which is basically a segmentation of the mesh triangles into subsets which will be turned into separate RenderBuffers in the Render Proxy.
Public function void When a FMeshChange or FMeshVertexChange is applied, by default we currently fully invalidate the render proxy.
Public function Virtual void IRenderMeshPostProcessor Support.
Public function void Set whether or not to validate mesh batch materials against the component materials.
Public function Virtual void

SetSimpleCollisionShapes ( const FKAggregateGeom& AggGeom,
bool bUpdateCollision
)

 Update the simple collision shapes associated with this mesh component
Public function void

SetTangentsType ( EDynamicMeshComponentTangentsMode NewTangentsType
)

  
Public function void The bDeferCollisionUpdates property is a serialized Component setting that controls when collision is regenerated.
Public function Virtual void

SetTriangleColorFunction ( TUniqueFunction< FColor(const FDynamicMesh3*, int)> TriangleColorFuncIn,
EDynamicMeshComponentRenderUpdateMode UpdateMode
)

 Support for specifying per-triangle colors as vertex colors.
Public function Virtual void

SetVertexColorRemappingFunction ( TUniqueFunction< void(FVector4f&)> ColorMapFuncIn,
EDynamicMeshComponentRenderUpdateMode UpdateMode
)

 Support for Vertex Color remapping/filtering.
Protected function void  
Public function Virtual void

UpdateCollision ( bool bOnlyIfPending
)

 Force an update of the Collision/Physics data for this Component.
Protected function void Recompute LocalBounds from the current Mesh
Public function bool

ValidateMaterialSlots ( bool bCreateIfMissing,
bool bDeleteExtraSlots
)

 Compute the maximum MaterialID on the DynamicMesh, and ensure that Material Slots match.

Overridden from UBaseDynamicMeshComponent

  Type Name Description
Public function Virtual void

ApplyTransform ( const FTransform3d& Transform,
bool bInvert
)

 Apply transform to internal mesh. In some cases this can be more efficient than a general edit.
Protected function Virtual FBaseDynamicMeshSceneProxy * Subclass must implement this to return scene proxy if available, or nullptr
Public function Virtual UDynamicMesh *  
Public function Virtual Const const FDynamicMesh3 *

GetMesh ()

 Avoid usage of this function, access via GetDynamicMesh() instead
Public function Virtual FDynamicMesh3 *

GetMesh ()

 Mesh Access.
Protected function Virtual void This is called to tell our RenderProxy about modifications to the material set.
Public function Virtual void RenderBuffer Update API.
Public function Virtual Const void

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

 Allow external code to read the internal mesh.
Public function Virtual void Initialize the internal mesh from a DynamicMesh

Overridden from UPrimitiveComponent

  Type Name Description
Protected function Virtual FPrimitiveSceneProxy * Creates a proxy to represent the primitive to the scene manager in the rendering thread.
Public function Virtual UBodySetup * Return the BodySetup to use for this PrimitiveComponent (single body case)

Overridden from USceneComponent

  Type Name Description
Protected function Virtual Const FBoxSphereBounds

CalcBounds ( const FTransform& LocalToWorld
)

 Calculate the bounds of the component. Default behavior is a bounding box/sphere of zero size.
Protected function Virtual void

OnChildAttached ( USceneComponent* ChildComponent
)

 Called after a child scene component is attached to this component.
Protected function Virtual void

OnChildDetached ( USceneComponent* ChildComponent
)

 Called after a child scene component is detached from this component.

Overridden from UObject

  Type Name Description
Protected function Virtual void Called before destroying the object.
Protected function Virtual void

PostEditChangeProperty ( FPropertyChangedEvent& PropertyChangedEvent
)

 Called when a property on this object has been modified externally
Protected function Virtual void Do any object-specific cleanup required immediately after loading an object.
Protected function Virtual void Handles reading, writing, and reference collecting using FArchive.

Overridden from IMeshVertexCommandChangeTarget

  Type Name Description
Public function Virtual void

ApplyChange ( const FMeshVertexChange* Change,
bool bRevert
)

 Change Support.

Overridden from IMeshCommandChangeTarget

  Type Name Description
Public function Virtual void

ApplyChange ( const FMeshChange* Change,
bool bRevert
)

 Apply a general mesh change to the mesh

Overridden from IMeshReplacementCommandChangeTarget

  Type Name Description
Public function Virtual void

ApplyChange ( const FMeshReplacementChange* Change,
bool bRevert
)

 Apply a mesh replacement change to mesh

Overridden from IInterface_CollisionDataProvider

  Type Name Description
Public function Virtual Const bool

ContainsPhysicsTriMeshData ( bool InUseAllTriData
)

 Interface for checking if the implementing objects contains triangle mesh collision data
Public function Virtual bool

GetPhysicsTriMeshData ( FTriMeshCollisionData* CollisionData,
bool InUseAllTriData
)

 Interface for retrieving triangle mesh collision data from the implementing object
Public function Virtual bool Do we want to create a negative version of this mesh

Typedefs

Name Description
FComponentChildrenChangedDelegate Support for Component attachment change notifications via delegates.
FMeshVerticesModified This delegate fires when the mesh vertices have been changed via an FMeshVertexChange

Constants

Name Description
UseDefaultTangentsType Default what the 'Default' tangent type should map to.

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