FConstraintProfileProperties Struct Reference

Container for properties of a physics constraint that can be easily swapped at runtime. This is useful for switching different setups when going from ragdoll to standup for example. More...

Public Member Functions
Functions
void	SetbEnableMassConditioning (bool Value)
	Whether mass conditioning is enabled for this joint. Mass conditioning applies a non-physical scale to the mass and inertia of the two bodies that only affects this joint, so that the mass and inertia ratios are smaller. This helps stabilize joints where the bodies are very different sizes, and especially when the parent body is heavier than the child. However, it can lead to unrealistic behaviour, especially when collisions are involved.
void	SetbDisableCollision (bool Value)
	Disable collision between bodies joined by this constraint.
void	SetbParentDominates (bool Value)
	When set, the parent body in a constraint will not be affected by the motion of the child.
void	SetbEnableShockPropagation (bool Value)
	Shock propagation increases the mass of the parent body for the last iteration of the position and velocity solve phases. This can help stiffen up joint chains, but is also prone to introducing energy down the chain especially at high alpha. It also does not work well if there are collisions on the bodies preventing the joints from correctly resolving - this can lead to jitter, especially if collision shock propagation is also enabled.
void	SetbEnableProjection (bool Value)
	Projection is a post-solve position and angular fixup consisting of two correction procedures. First, if the constraint limits are exceeded by more that the Linear or Angular Tolerance, the bodies are teleported to eliminate the error. Second, if the constraint limits are exceeded by less than the tolerance, a semi-physical correction is applied, with the parent body in the constraint is treated as having infinite mass. The teleport tolerance are controlled by ProjectionLinearTolerance and ProjectionAngularTolerance. The semi-physical correction is controlled by ProjectionLinearAlpha and ProjectionAnguilarAlpha. You may have one, none, or both systems enabled at the same time.
FConstraintProfileProperties &	opAssign (FConstraintProfileProperties Other)
void	SetbAngularBreakable (bool Value)
	Whether it is possible to break the joint with angular force.
void	SetbAngularPlasticity (bool Value)
	Whether it is possible to reset target rotations from the angular displacement.
void	SetbLinearBreakable (bool Value)
	Whether it is possible to break the joint with linear force.
void	SetbLinearPlasticity (bool Value)
	Whether it is possible to reset spring rest length from the linear deformation.

Public Attributes
Angular
float32	AngularPlasticityThreshold
	[Chaos Only] Degree threshold from target angle needed to reset the target angle.
float32	AngularBreakThreshold
	Torque needed to break the joint.
FTwistConstraint	TwistLimit
FConeConstraint	ConeLimit
FAngularDriveConstraint	AngularDrive
Linear
float32	LinearBreakThreshold
	Force needed to break the distance constraint.
float32	LinearPlasticityThreshold
	[Chaos Only] Percent threshold from center of mass distance needed to reset the linear drive position target. This value can be greater than 1.
EConstraintPlasticityType	LinearPlasticityType
	Whether linear plasticity has a operation mode [free].
float32	ContactTransferScale
	[Chaos Only] Colliison transfer on parent from the joints child. Range is 0.0-MAX
FLinearConstraint	LinearLimit
FLinearDriveConstraint	LinearDrive
Projection
float32	ShockPropagationAlpha
	How much shock propagation to apply [0-1]. Shock propagation increases the mass of the parent body for the last iteration of the position and velocity solve phases. This can help stiffen up joint chains, but is also prone to introducing energy down the chain especially at high alpha. Only used in bEnableShockPropagation is true.
float32	ProjectionAngularAlpha
	How much semi-physical angular projection correction to apply [0-1]. Only used if bEnableProjection is true and if hard limits are used.
float32	ProjectionLinearAlpha
	How much semi-physical linear projection correction to apply [0-1]. Only used if bEnableProjection is true and if hard limits are used.
float32	ProjectionAngularTolerance
	If the joint error is above this distance after the solve phase, the child body will be teleported to fix the error. Only used if bEnableProjection is true.
float32	ProjectionLinearTolerance
	If the joint error is above this distance after the solve phase, the child body will be teleported to fix the error. Only used if bEnableProjection is true.

Detailed Description

Container for properties of a physics constraint that can be easily swapped at runtime. This is useful for switching different setups when going from ragdoll to standup for example.

Member Function Documentation

opAssign()

FConstraintProfileProperties & opAssign

(

FConstraintProfileProperties

Other

)

SetbAngularBreakable()

void SetbAngularBreakable

(

bool

Value

)

Whether it is possible to break the joint with angular force.

SetbAngularPlasticity()

void SetbAngularPlasticity

(

bool

Value

)

Whether it is possible to reset target rotations from the angular displacement.

SetbDisableCollision()

void SetbDisableCollision

(

bool

Value

)

Disable collision between bodies joined by this constraint.

SetbEnableMassConditioning()

void SetbEnableMassConditioning

(

bool

Value

)

Whether mass conditioning is enabled for this joint. Mass conditioning applies a non-physical scale to the mass and inertia of the two bodies that only affects this joint, so that the mass and inertia ratios are smaller. This helps stabilize joints where the bodies are very different sizes, and especially when the parent body is heavier than the child. However, it can lead to unrealistic behaviour, especially when collisions are involved.

SetbEnableProjection()

void SetbEnableProjection

(

bool

Value

)

Projection is a post-solve position and angular fixup consisting of two correction procedures. First, if the constraint limits are exceeded by more that the Linear or Angular Tolerance, the bodies are teleported to eliminate the error. Second, if the constraint limits are exceeded by less than the tolerance, a semi-physical correction is applied, with the parent body in the constraint is treated as having infinite mass. The teleport tolerance are controlled by ProjectionLinearTolerance and ProjectionAngularTolerance. The semi-physical correction is controlled by ProjectionLinearAlpha and ProjectionAnguilarAlpha. You may have one, none, or both systems enabled at the same time.

Projection only works well if the chain is not interacting with other objects (e.g., through collisions) because the projection of the bodies in the chain will cause other constraints to be violated. Likewise, if a body is influenced by multiple constraints, then enabling projection on more than one constraint may lead to unexpected results - the "last" constraint would win but the order in which constraints are solved cannot be directly controlled.

Note that the semi-physical projection (ProjectionLinearAlpha and ProjectionAngularAlpha) is only applied to hard-limit constraints and not those with soft limits because the soft limit is the point at which the soft-constraint (spring) kicks in, and not really a limit on how far the joint can be separated.

SetbEnableShockPropagation()

void SetbEnableShockPropagation

(

bool

Value

)

Shock propagation increases the mass of the parent body for the last iteration of the position and velocity solve phases. This can help stiffen up joint chains, but is also prone to introducing energy down the chain especially at high alpha. It also does not work well if there are collisions on the bodies preventing the joints from correctly resolving - this can lead to jitter, especially if collision shock propagation is also enabled.

SetbLinearBreakable()

void SetbLinearBreakable

(

bool

Value

)

Whether it is possible to break the joint with linear force.

SetbLinearPlasticity()

void SetbLinearPlasticity

(

bool

Value

)

Whether it is possible to reset spring rest length from the linear deformation.

SetbParentDominates()

void SetbParentDominates

(

bool

Value

)

When set, the parent body in a constraint will not be affected by the motion of the child.

Member Data Documentation

AngularBreakThreshold

float32 AngularBreakThreshold

Torque needed to break the joint.

AngularDrive

FAngularDriveConstraint AngularDrive

AngularPlasticityThreshold

float32 AngularPlasticityThreshold

[Chaos Only] Degree threshold from target angle needed to reset the target angle.

ConeLimit

FConeConstraint ConeLimit

ContactTransferScale

float32 ContactTransferScale

[Chaos Only] Colliison transfer on parent from the joints child. Range is 0.0-MAX

LinearBreakThreshold

float32 LinearBreakThreshold

Force needed to break the distance constraint.

LinearDrive

FLinearDriveConstraint LinearDrive

LinearLimit

FLinearConstraint LinearLimit

LinearPlasticityThreshold

float32 LinearPlasticityThreshold

[Chaos Only] Percent threshold from center of mass distance needed to reset the linear drive position target. This value can be greater than 1.

LinearPlasticityType

EConstraintPlasticityType LinearPlasticityType

Whether linear plasticity has a operation mode [free].

ProjectionAngularAlpha

float32 ProjectionAngularAlpha

How much semi-physical angular projection correction to apply [0-1]. Only used if bEnableProjection is true and if hard limits are used.

ProjectionAngularTolerance

float32 ProjectionAngularTolerance

If the joint error is above this distance after the solve phase, the child body will be teleported to fix the error. Only used if bEnableProjection is true.

ProjectionLinearAlpha

float32 ProjectionLinearAlpha

How much semi-physical linear projection correction to apply [0-1]. Only used if bEnableProjection is true and if hard limits are used.

ProjectionLinearTolerance

float32 ProjectionLinearTolerance

If the joint error is above this distance after the solve phase, the child body will be teleported to fix the error. Only used if bEnableProjection is true.

ShockPropagationAlpha

float32 ShockPropagationAlpha

How much shock propagation to apply [0-1]. Shock propagation increases the mass of the parent body for the last iteration of the position and velocity solve phases. This can help stiffen up joint chains, but is also prone to introducing energy down the chain especially at high alpha. Only used in bEnableShockPropagation is true.

TwistLimit

FTwistConstraint TwistLimit