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  3. UNiagaraDataInterfaceHairStrands

UNiagaraDataInterfaceHairStrands

Data Interface for the strand base

Unreal Engine C++ API Reference > Plugins > HairStrandsCore > Niagara

Inheritance Hierarchy

References

   
Module HairStrandsCore
Header /Engine/Plugins/Runtime/HairStrands/Source/HairStrandsCore/Public/Niagara/NiagaraDataInterfaceHairStrands.h
Include #include "Niagara/NiagaraDataInterfaceHairStrands.h"

Syntax

UCLASS&40;EditInlineNew, Category&61;"Strands", Meta&61;&40;DisplayName&61;"Hair Strands"&41;&41;  
class UNiagaraDataInterfaceHairStrands :  
    public UNiagaraDataInterface,  
    public INiagaraSimCacheCustomStorageInterface

Remarks

Data Interface for the strand base

Variables

  Type Name Description
Public variable UProperty Category, EditAnywhere TObjectPtr< UGroomAsset > DefaultSource Hair Strands Asset used to sample from when not overridden by a source actor from the scene.
Public variable UProperty Category, EditAnywhere TObjectPtr< AActor > SourceActor The source actor from which to sample
Public variable TWeakObjectPtr< class UGroomComponent > SourceComponent The source component from which to sample

Constructors

  Type Name Description
Public function    

Functions

  Type Name Description
Public function void

AdvectNodeOrientation ( FVectorVMExternalFunctionContext& Context
)

 Add external torque to the angular velocity and advect node orientation
Public function void

AdvectNodePosition ( FVectorVMExternalFunctionContext& Context
)

 Add external force to the linear velocity and advect node position
Public function void

AttachNodeOrientation ( FVectorVMExternalFunctionContext& Context
)

 Update the root node position based on the current transform
Public function void

AttachNodePosition ( FVectorVMExternalFunctionContext& Context
)

 Update the root node orientation based on the current transform
Public function void

AttachNodeState ( FVectorVMExternalFunctionContext& Context
)

 Attach the node position and orientation to the transform or to the skin cache
Public function void

BuildBoundingBox ( FVectorVMExternalFunctionContext& Context
)

 Build the groom bounding box
Public function void

ComputeAirDragForce ( FVectorVMExternalFunctionContext& Context
)

 Compute the air drag force
Public function void

ComputeEdgeDirection ( FVectorVMExternalFunctionContext& Context
)

 Compute the rest direction
Public function void

ComputeEdgeLength ( FVectorVMExternalFunctionContext& Context
)

 Compute the edge length (diff between 2 nodes positions)
Public function void

ComputeEdgeRotation ( FVectorVMExternalFunctionContext& Context
)

 Compute the edge orientation (diff between 2 nodes orientations)
Public function void

ComputeLocalState ( FVectorVMExternalFunctionContext& Context
)

 Get the rest position and orientation relative to the transform or to the skin cache
Public function void

ComputeMaterialFrame ( FVectorVMExternalFunctionContext& Context
)

 Compute the strands material frame
Public function void

ComputeNodeInertia ( FVectorVMExternalFunctionContext& Context
)

 Get the strand node inertia
Public function void

ComputeNodeMass ( FVectorVMExternalFunctionContext& Context
)

 Get the strand node mass
Public function void

ComputeNodeOrientation ( FVectorVMExternalFunctionContext& Context
)

 Get the strand node orientation in world space
Public function void

ComputeNodePosition ( FVectorVMExternalFunctionContext& Context
)

 Get the strand node position in world space
Public function void

ComputeRestOrientation ( FVectorVMExternalFunctionContext& Context
)

 Compute the rest local orientation
Public function void

ComputeRestPosition ( FVectorVMExternalFunctionContext& Context
)

 Compute the rest local position
Public function void

EvalSkinnedPosition ( FVectorVMExternalFunctionContext& Context
)

 Eval the skinned position given a rest position
Public function void

ExtractDatasAndResources ( FNiagaraSystemInstance* SystemInstance,
FHairStrandsRestResource*& OutStrandsRestResource,
FHairStrandsDeformedResource*& OutStrandsDeformedResource,
FHairStrandsRestRootResource*& OutStrandsRestRootResource,
FHairStrandsDeformedRootResource*& OutStrandsDeformedRootResource,
UGroomAsset*& OutGroomAsset,
int32& OutGroupIndex,
int32& OutLODIndex,
FTransform& OutLocalToWorld
)

 Extract datas and resources
Public function void End INiagaraSimCacheCustomStorageInterface Interface Update the source component
Public function void

GetAirDrag ( FVectorVMExternalFunctionContext& Context
)

  
Public function void

GetAirVelocity ( FVectorVMExternalFunctionContext& Context
)

  
Public function void

GetBendDamping ( FVectorVMExternalFunctionContext& Context
)

  
Public function void

GetBendScale ( FVectorVMExternalFunctionContext& Context
)

  
Public function void

GetBendStiffness ( FVectorVMExternalFunctionContext& Context
)

  
Public function void

GetBoundingBox ( FVectorVMExternalFunctionContext& Context
)

 Get the bounding box center
Public function void

GetCollisionRadius ( FVectorVMExternalFunctionContext& Context
)

  
Public function void

GetGravityPreloading ( FVectorVMExternalFunctionContext& Context
)

  
Public function void

GetGravityVector ( FVectorVMExternalFunctionContext& Context
)

  
Public function void

GetGridDimension ( FVectorVMExternalFunctionContext& Context
)

  
Public function void

GetIterationCount ( FVectorVMExternalFunctionContext& Context
)

  
Public function void

GetKineticFriction ( FVectorVMExternalFunctionContext& Context
)

  
Public function void

GetNumStrands ( FVectorVMExternalFunctionContext& Context
)

 Get the number of strands
Public function void

GetPointPosition ( FVectorVMExternalFunctionContext& Context
)

 Get the strand vertex position in world space
Public function void

GetProjectBend ( FVectorVMExternalFunctionContext& Context
)

  
Public function void

GetProjectCollision ( FVectorVMExternalFunctionContext& Context
)

  
Public function void

GetProjectStretch ( FVectorVMExternalFunctionContext& Context
)

  
Public function void

GetRadiusScale ( FVectorVMExternalFunctionContext& Context
)

  
Public function void

GetSampleState ( FVectorVMExternalFunctionContext& Context
)

 Get the sample state given an index
Public function void

GetSolveBend ( FVectorVMExternalFunctionContext& Context
)

  
Public function void

GetSolveCollision ( FVectorVMExternalFunctionContext& Context
)

  
Public function void

GetSolveStretch ( FVectorVMExternalFunctionContext& Context
)

  
Public function void

GetStaticFriction ( FVectorVMExternalFunctionContext& Context
)

  
Public function void

GetStrandsDensity ( FVectorVMExternalFunctionContext& Context
)

  
Public function void

GetStrandSize ( FVectorVMExternalFunctionContext& Context
)

 Get the groom asset datas
Public function void

GetStrandsSmoothing ( FVectorVMExternalFunctionContext& Context
)

  
Public function void

GetStrandsThickness ( FVectorVMExternalFunctionContext& Context
)

  
Public function void

GetStrandsViscosity ( FVectorVMExternalFunctionContext& Context
)

  
Public function void

GetStretchDamping ( FVectorVMExternalFunctionContext& Context
)

  
Public function void

GetStretchScale ( FVectorVMExternalFunctionContext& Context
)

  
Public function void

GetStretchStiffness ( FVectorVMExternalFunctionContext& Context
)

  
Public function void

GetSubSteps ( FVectorVMExternalFunctionContext& Context
)

  
Public function void

GetThicknessScale ( FVectorVMExternalFunctionContext& Context
)

  
Public function void

GetWorldInverse ( FVectorVMExternalFunctionContext& Context
)

 Get the world inverse
Public function void

GetWorldTransform ( FVectorVMExternalFunctionContext& Context
)

 Get the world transform
Public function void

HasGlobalInterpolation ( FVectorVMExternalFunctionContext& Context
)

 Check if we have a global interpolation
Public function void

InitGridSamples ( FVectorVMExternalFunctionContext& Context
)

 Init the samples along the strands that will be used to transfer informations to the grid
Public function Const bool Check if the component is Valid
Public function void

NeedRestUpdate ( FVectorVMExternalFunctionContext& Context
)

 Check if we need a rest pose update
Public function void

NeedSimulationReset ( FVectorVMExternalFunctionContext& Context
)

 Check if we need or not a simulation reset
Public function void

ProjectAngularSpringMaterial ( FVectorVMExternalFunctionContext& Context
)

 Project the angular spring material
Public function void

ProjectBendRodMaterial ( FVectorVMExternalFunctionContext& Context
)

 Project the bend rod material
Public function void

ProjectDistanceSpringMaterial ( FVectorVMExternalFunctionContext& Context
)

 Project the distance spring material
Public function void

ProjectHardCollisionConstraint ( FVectorVMExternalFunctionContext& Context
)

 Project the static collision constraint
Public function void

ProjectSoftCollisionConstraint ( FVectorVMExternalFunctionContext& Context
)

 Project the soft collision constraint
Public function void

ProjectStretchRodMaterial ( FVectorVMExternalFunctionContext& Context
)

 Project the stretch rod material
Public function void

ResetBoundingBox ( FVectorVMExternalFunctionContext& Context
)

 Reset the bounding box extent
Public function void

ResetPointPosition ( FVectorVMExternalFunctionContext& Context
)

 Reset the point position to be the rest one
Public function void

SetupAngularSpringMaterial ( FVectorVMExternalFunctionContext& Context
)

 Setup the angular spring material
Public function void

SetupBendRodMaterial ( FVectorVMExternalFunctionContext& Context
)

 Setup the bend rod material
Public function void

SetupDistanceSpringMaterial ( FVectorVMExternalFunctionContext& Context
)

 Setup the distance spring material
Public function void

SetupSoftCollisionConstraint ( FVectorVMExternalFunctionContext& Context
)

 Setup the soft collision constraint
Public function void

SetupStretchRodMaterial ( FVectorVMExternalFunctionContext& Context
)

 Setup the stretch rod material
Public function void

SolveAngularSpringMaterial ( FVectorVMExternalFunctionContext& Context
)

 Solve the angular spring material
Public function void

SolveBendRodMaterial ( FVectorVMExternalFunctionContext& Context
)

 Solve the bend rod material
Public function void

SolveDistanceSpringMaterial ( FVectorVMExternalFunctionContext& Context
)

 Solve the distance spring material
Public function void

SolveHardCollisionConstraint ( FVectorVMExternalFunctionContext& Context
)

 Solve the static collision constraint
Public function void

SolveSoftCollisionConstraint ( FVectorVMExternalFunctionContext& Context
)

 Solve the soft collision constraint
Public function void

SolveStretchRodMaterial ( FVectorVMExternalFunctionContext& Context
)

 Solve the stretch rod material
Public function void

UpdateAngularVelocity ( FVectorVMExternalFunctionContext& Context
)

 Update the node angular velocity based on the node orientation difference
Public function void

UpdateLinearVelocity ( FVectorVMExternalFunctionContext& Context
)

 Update the node linear velocity based on the node position difference
Public function void

UpdateMaterialFrame ( FVectorVMExternalFunctionContext& Context
)

 Update the strands material frame
Public function void

UpdateNodeState ( FVectorVMExternalFunctionContext& Context
)

 Update the node position and orientation based on rbf transfer
Public function void

UpdatePointPosition ( FVectorVMExternalFunctionContext& Context
)

 Report the node displacement onto the points position

Overridden from UNiagaraDataInterface

  Type Name Description
Public function Virtual Const bool Allows the generic class defaults version of this class to specify any dependencies/version/etc that might invalidate the compile.
Public function Virtual Const ETickingGroup

CalculateTickGroup ( const void* PerInstanceData
)

  
Public function Virtual Const bool  
Protected function Virtual Const bool Copy one niagara DI to this
Public function Virtual void

DestroyPerInstanceData ( void* PerInstanceData,
FNiagaraSystemInstance* SystemInstance
)

 Destroys the per instance data for this interface.
Public function Virtual Const bool

Equals ( const UNiagaraDataInterface* Other
)

 Determines if this DataInterface is the same as another.
Public function Virtual void

GetCommonHLSL ( FString& OutHLSL
)

 GPU simulation functionality
Public function Virtual bool

GetFunctionHLSL ( const FNiagaraDataInterfaceGPUParamInfo& ParamInfo,
const FNiagaraDataInterfaceGeneratedFunction& FunctionInfo,
int FunctionInstanceIndex,
FString& OutHLSL
)

  
Public function Virtual void Begin UNiagaraDataInterface Interface
Public function Virtual void  
Public function Virtual void

GetVMExternalFunction ( const FVMExternalFunctionBindingInfo& BindingInfo,
void* InstanceData,
FVMExternalFunction& OutFunc
)

 Returns the delegate for the passed function signature.
Public function Virtual Const bool  
Public function Virtual Const bool  
Public function Virtual bool

InitPerInstanceData ( void* PerInstanceData,
FNiagaraSystemInstance* SystemInstance
)

 Initializes the per instance data for this interface.
Public function Virtual Const int32 Returns the size of the per instance data for this interface.
Public function Virtual bool

PerInstanceTick ( void* PerInstanceData,
FNiagaraSystemInstance* SystemInstance,
float DeltaSeconds
)

 Ticks the per instance data for this interface, if it has any.
Public function Virtual void

ProvidePerInstanceDataForRenderThread ( void* DataForRenderThread,
void* PerInstanceData,
const FNiagaraSystemInstanceID& SystemInstance
)

 Subclasses that wish to work with GPU systems/emitters must implement this.
Public function Virtual Const void Set the shader parameters will only be called if the data interface provided shader parameters.

Overridden from UNiagaraDataInterfaceBase

  Type Name Description
Public function Virtual Const void Override this method to provide parameters to the GPU (SRV / UAV / Constants / etc) The most common usage will be to provide a single structure which is nested with other parameters.

Overridden from UObject

  Type Name Description
Public function Virtual void UObject Interface

Overridden from INiagaraSimCacheCustomStorageInterface

  Type Name Description
Public function Virtual Const TArray< FNiagaraVariableBase > This function allows you to preserve a list of attributes when building a renderer only cache.
Public function Virtual void

SimCachePostReadFrame ( void* OptionalPerInstanceData,
FNiagaraSystemInstance* SystemInstance
)

 End UNiagaraDataInterface Interface Begin INiagaraSimCacheCustomStorageInterface Interface

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