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  3. FAnimPhys

FAnimPhys

Lightweight rigid body motion solver (no collision) used for cosmetic secondary motion in an animation graph without invoking something heavier like using PhysX to simulate constraints which could be cost prohibitive

API > API/Runtime > API/Runtime/Engine

Lightweight rigid body motion solver (no collision) used for cosmetic secondary motion in an animation graph without invoking something heavier like using PhysX to simulate constraints which could be cost prohibitive

   
Name FAnimPhys
Type class
Header File /Engine/Source/Runtime/Engine/Public/Animation/AnimPhysicsSolver.h
Include Path #include "Animation/AnimPhysicsSolver.h"

Syntax

class FAnimPhys

Constants

Name Type Remarks Include Path
AngularAccelerationAlpha float How much of the simulation frame's angular acceleration to pass onto the sim bodies. Animation/AnimPhysicsSolver.h
bEnableDetailedStats bool Runtime CVar toggle for detailed/verbose profiling. Animation/AnimPhysicsSolver.h
CentrifugalAlpha float How much of the centrifugal force to apply to the sim bodies. Animation/AnimPhysicsSolver.h
CoriolisAlpha float How much of the coriolis force to apply to the sim bodies. Animation/AnimPhysicsSolver.h
EulerAlpha float How much of the euler force to apply to the sim bodies. Animation/AnimPhysicsSolver.h

Functions

Static

Name Remarks Include Path Unreal Specifiers

static void ApplyImpulse ( FAnimPhysRigidBody* InOutRigidBody,
const FVector& InWorldOrientedImpactPoint,
const FVector& InImpulse
)

 Apply an impulse to a body Animation/AnimPhysicsSolver.h  

static FVector CalculateCenterOfMass ( const TArray< FVector >& InVertices,
const TArray< FIntVector >& InTriangles
)

 Calculates the center of mass of a shape Animation/AnimPhysicsSolver.h  

static FVector CalculateCenterOfMass ( const TArray< FAnimPhysShape >& InShapes
)

 Calculates the centre of mass of a collection of shapes Animation/AnimPhysicsSolver.h  

static FMatrix CalculateInertia ( const TArray< FVector >& InVertices,
const TArray< FIntVector >& InTriangles,
const FVector& InCenterOfMass
)

 Calculate the inertia tensor of a shape Animation/AnimPhysicsSolver.h  

static FMatrix CalculateInertia ( const TArray< FAnimPhysShape >& InShapes,
const FVector& InCenterOfMass
)

 Calculate the inertia tensor of a collection of shapes Animation/AnimPhysicsSolver.h  

static void CalculateNextPose ( float DeltaTime,
FAnimPhysRigidBody* InBody
)

 Using calculated linear and angular momentum, integrate the position and orientation of a body Animation/AnimPhysicsSolver.h  

static float CalculateVolume ( const TArray< FAnimPhysShape >& InShapes
)

 Calculates the volume of a collection of shapes Animation/AnimPhysicsSolver.h  

static float CalculateVolume ( const TArray< FVector >& InVertices,
const TArray< FIntVector >& InTriangles
)

 Calculates the volume of a shape Animation/AnimPhysicsSolver.h  

static void ConstrainAlongDirection ( float DeltaTime,
TArray< FAnimPhysLinearLimit >& LimitContainer,
FAnimPhysRigidBody* FirstBody,
const FVector& FirstPosition,
FAnimPhysRigidBody* SecondBody,
const FVector& SecondPosition,
const FVector& AxisToConstrain,
const FVector2D Limits,
float MinimumForce,
float MaximumForce
)

 Constrain bodies along a provided axis Animation/AnimPhysicsSolver.h  

static void ConstrainAngularRange ( float DeltaTime,
TArray< FAnimPhysAngularLimit >& LimitContainer,
FAnimPhysRigidBody* FirstBody,
FAnimPhysRigidBody* SecondBody,
const FQuat& JointFrame,
AnimPhysTwistAxis TwistAxis,
const FVector& JointLimitMin,
const FVector& JointLimitMax,
float InJointBias
)

 Constraint two bodies together with angular limits, limiting the relative rotation between them. Animation/AnimPhysicsSolver.h  

static void ConstrainAngularRangeInternal ( float DeltaTime,
TArray< FAnimPhysAngularLimit >& LimitContainer,
FAnimPhysRigidBody* FirstBody,
const FQuat& JointFrame0,
FAnimPhysRigidBody* SecondBody,
const FQuat& JointFrame1,
AnimPhysTwistAxis TwistAxis,
const FVector& InJointLimitMin,
const FVector& InJointLimitMax,
float InJointBias
)

 Internal version of constrain angular. Animation/AnimPhysicsSolver.h  

static void ConstrainConeAngle ( float DeltaTime,
TArray< FAnimPhysAngularLimit >& LimitContainer,
FAnimPhysRigidBody* FirstBody,
const FVector& Normal0,
FAnimPhysRigidBody* SecondBody,
const FVector& Normal1,
float LimitAngle,
float InJointBias
)

 Constraints the rotation between two bodies into a cone Animation/AnimPhysicsSolver.h  

static void ConstrainPlanar ( float DeltaTime,
TArray< FAnimPhysLinearLimit >& LimitContainer,
FAnimPhysRigidBody* Body,
const FTransform& PlaneTransform
)

 Constrains the position of a body to one side of a plane placed at PlaneTransform (plane normal is Z axis) Animation/AnimPhysicsSolver.h  

static void ConstrainPositionNailed ( float DeltaTime,
TArray< FAnimPhysLinearLimit >& LimitContainer,
FAnimPhysRigidBody* FirstBody,
const FVector& FirstPosition,
FAnimPhysRigidBody* SecondBody,
const FVector& SecondPosition
)

 Constrain bodies together as if fixed or nailed (linear only, bodies can still rotate) Animation/AnimPhysicsSolver.h  

static void ConstrainPositionPrismatic ( float DeltaTime,
TArray< FAnimPhysLinearLimit >& LimitContainer,
FAnimPhysRigidBody* FirstBody,
const FVector& FirstPosition,
FAnimPhysRigidBody* SecondBody,
const FVector& SecondPosition,
const FQuat& PrismRotation,
const FVector& LimitsMin,
const FVector& LimitsMax
)

 Constrain bodies together with linear limits forming a box or prism around the constraint Animation/AnimPhysicsSolver.h  

static void ConstrainSphericalInner ( float DeltaTime,
TArray< FAnimPhysLinearLimit >& LimitContainer,
FAnimPhysRigidBody* Body,
const FTransform& SphereTransform,
float SphereRadius
)

 Constrains the position of a body within the requested sphere Animation/AnimPhysicsSolver.h  

static void ConstrainSphericalOuter ( float DeltaTime,
TArray< FAnimPhysLinearLimit >& LimitContainer,
FAnimPhysRigidBody* Body,
const FTransform& SphereTransform,
float SphereRadius
)

 Constrains the position of a body outside of the requested sphere Animation/AnimPhysicsSolver.h  

static void CreateSpring ( TArray< FAnimPhysSpring >& SpringContainer,
FAnimPhysRigidBody* Body0,
FVector Position0,
FAnimPhysRigidBody* Body1,
FVector Position1
)

 Spring creation methods. Animation/AnimPhysicsSolver.h  

static FQuat DiffQ ( const FQuat& InOrientation,
const FMatrix& InInverseTensor,
const FVector& InAngularMomentum
)

 Calculate differentiated orientation quaternion Animation/AnimPhysicsSolver.h  

static void InitializeBodyVelocity ( float DeltaTime,
FAnimPhysRigidBody* InBody,
const FVector& GravityDirection
)

 Initialize the velocity for a given body Animation/AnimPhysicsSolver.h  

static void PhysicsUpdate ( float DeltaTime,
TArray< FAnimPhysRigidBody* >& Bodies,
TArray< FAnimPhysLinearLimit >& LinearLimits,
TArray< FAnimPhysAngularLimit >& AngularLimits,
TArray< FAnimPhysSpring >& Springs,
const FVector& GravityDirection,
const FVector& ExternalForce,
const FVector& ExternalLinearAcc,
const FVector& ExternalAngularAcc,
const FVector& ExternalAngularVelocity,
int32 NumPreIterations,
int32 NumPostIterations
)

 Performs a physics update on the provided state objects Animation/AnimPhysicsSolver.h  

static void ScaleRigidBodyMass ( FAnimPhysRigidBody* InOutRigidBody,
float Scale
)

 Scale the mass and inertia properties of a rigid body Animation/AnimPhysicsSolver.h  

static FQuat UpdateOrientRK ( const FQuat& InOrient,
const FMatrix& InInverseTensor,
const FVector& InAngularMomentum,
float InDeltaTime
)

 Perform an RK update of the provided orientation Animation/AnimPhysicsSolver.h  

static void UpdatePose ( FAnimPhysRigidBody* InBody
)

 Update previous and current pose state Animation/AnimPhysicsSolver.h  

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