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SpringMath

Collection of useful spring methods which can be used for damping, simulating characters etc.

API > API/Runtime > API/Runtime/Engine

Collection of useful spring methods which can be used for damping, simulating characters etc. Reference https://theorangeduck.com/page/spring-roll-call

   
Name SpringMath
Type struct
Header File /Engine/Source/Runtime/Engine/Public/Animation/SpringMath.h
Include Path #include "Animation/SpringMath.h"

Syntax

struct SpringMath

Functions

Static

Name Remarks Include Path Unreal Specifiers

static void CriticalSpringDamper ( T& InOutX,
T& InOutV,
T TargetX,
float SmoothingTime,
float DeltaTime
)

 Simplified version of FMath::CriticallyDampedSmoothing where v_goal is assumed to be 0. Animation/SpringMath.h  

static void CriticalSpringDamperAngle ( float& InOutAngleRadians,
float& InOutAngularVelocityRadians,
float TargetAngleRadians,
float SmoothingTime,
float DeltaTime
)

 Specialized angle version of CriticalSpringDamper that handles angle wrapping. Animation/SpringMath.h  

static void CriticalSpringDamperQuat ( FQuat& InOutRotation,
FVector& InOutAngularVelocityRadians,
const FQuat& TargetRotation,
float SmoothingTime,
float DeltaTime
)

 Specialized quaternion version of CriticalSpringDamper, uses FVector for angular velocity Animation/SpringMath.h  

static void CriticalSpringDamperQuatPredict ( TArrayView< FQuat > OutPredictedRotations,
TArrayView< FVector > OutPredictedAngularVelocities,
int32 PredictCount,
const FQuat& CurrentRotation,
const FVector& CurrentAngularVelocity,
const FQuat& TargetRotation,
float SmoothingTime,
float SecondsPerPredictionStep
)

 Prediction of CriticalSpringDamperQuat Animation/SpringMath.h  

static void ExponentialSmoothingApproxAngle ( float& InOutAngleRadians,
const float& InTargetAngleRadians,
const float InDeltaTime,
const float InSmoothingTime
)

 Specialized angle damper, similar to FMath::ExponentialSmoothingApprox but deals correctly with angle wrap-around. Animation/SpringMath.h  

static void ExponentialSmoothingApproxQuat ( FQuat& InOutRotation,
const FQuat& InTargetRotation,
const float InDeltaTime,
const float InSmoothingTime
)

 Specialized quaternion damper, similar to FMath::ExponentialSmoothingApprox but for quaternions. Animation/SpringMath.h  

static float HalfLifeToSmoothingTime ( float HalfLife
)

 Convert a halflife to a smoothing time Animation/SpringMath.h  

static float SmoothingTimeToDamping ( float SmoothingTime
)

   Animation/SpringMath.h  

static float SmoothingTimeToHalfLife ( float SmoothingTime
)

 Convert a smoothing time to a half life Animation/SpringMath.h  

static float SmoothingTimeToStrength ( float SmoothingTime
)

 Convert from smoothing time to spring strength. Animation/SpringMath.h  

static void SpringCharacterPredict ( TArrayView< TVector > OutPredictedPositions,
TArrayView< TVector > OutPredictedVelocities,
TArrayView< TVector > OutPredictedAccelerations,
const TVector& CurrentPosition,
const TVector& CurrentVelocity,
const TVector& CurrentAcceleration,
const TVector& TargetVelocity,
float SmoothingTime,
float SecondsPerPredictionStep,
float VDeadzone,
float ADeadzone
)

 Gives predicted positions, velocities and accelerations for SpringCharacterUpdate. Animation/SpringMath.h  

static void SpringCharacterUpdate ( TVector& InOutPosition,
TVector& InOutVelocity,
TVector& InOutAcceleration,
const TVector& TargetVelocity,
float SmoothingTime,
float DeltaTime,
float VDeadzone,
float ADeadzone
)

 Update the position of a character given a target velocity using a simple damped spring Animation/SpringMath.h  

static float StrengthToSmoothingTime ( float Strength
)

 Convert from spring strength to smoothing time. Animation/SpringMath.h  

static void VelocitySpringCharacterPredict ( TArrayView< TVector > OutPredictedPositions,
TArrayView< TVector > OutPredictedVelocities,
TArrayView< TVector > OutPredictedIntermediateVelocities,
TArrayView< TVector > OutPredictedAccelerations,
const TVector& CurrentPosition,
const TVector& CurrentVelocity,
const TVector& CurrentIntermediateVelocity,
const TVector& CurrentAcceleration,
const TVector& TargetVelocity,
float SmoothingTime,
float MaxAcceleration,
float SecondsPerPredictionStep,
float VDeadzone,
float ADeadzone
)

 Gives predicted positions, velocities and accelerations for SpringCharacterUpdate. Animation/SpringMath.h  

static void VelocitySpringCharacterUpdate ( TVector& InOutPosition,
TVector& InOutVelocity,
TVector& InOutVelocityIntermediate,
TVector& InOutAcceleration,
TVector TargetVelocity,
float SmoothingTime,
float MaxAcceleration,
float DeltaTime,
float VDeadzone,
float ADeadzone
)

 Update a position representing a character given a target velocity using a velocity spring. Animation/SpringMath.h  

static void VelocitySpringDamper ( TVector& InOutX,
TVector& InOutV,
TVector& InOutXi,
TVector TargetX,
float MaxSpeed,
float SmoothingTime,
float DeltaTime
)

 A velocity spring will damp towards a target that follows a fixed linear target velocity, allowing control of the interpolation speed while still giving a smoothed behaviour. Animation/SpringMath.h  

static void VelocitySpringDamperF ( TFloat& InOutX,
TFloat& InOutV,
TFloat& InOutXi,
TFloat TargetX,
TFloat MaxSpeed,
float SmoothingTime,
float DeltaTime
)

 A velocity spring will damp towards a target that follows a fixed linear target velocity, allowing control of the interpolation speed while still giving a smoothed behavior. Animation/SpringMath.h  

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