Physics

(NOTE) Information to represent a constraint to be solved. The main information that needs to be set here is the Jacobian and error. A constraint will enforce that the relative velocities along the Jacobian are equal to zero (ignoring error correction or motors).

Methods	Properties	Base Classes
ComputeMotor	Active	referencecountedeventobject
ComputeSpring	Angular0
DetachFromOwner	Angular1
IsOwned	Baumgarte
SetErrorAndBias	Bias
SetJacobian	EffectiveMass
	Error
	Gamma
	Impulse
	Linear0
	Linear1
	MaxImpulse
	MinImpulse
	Owner
	SolvePosition

Properties

Active : boolean

Is this constraint currently active?
var Active : Boolean

Angular0 : real3

Angular portion of objectA's Jacobian.
var Angular0 : Real3

Angular1 : real3

Angular portion of objectB's Jacobian.
var Angular1 : Real3

Baumgarte : real

The baumgarte term used to correct error. This should typically be set in initialization (per constraint) and then left alone. Default value is 5.
var Baumgarte : Real

Bias : real

The bias is used to apply energy into the system. Typically, bias is combined with Error and Baumgarte to fix error. Bias is also used for motors and springs to drive the constraint.
var Bias : Real

EffectiveMass : real

The effective mass of the constraint. This is typically set by calling SetJacobian.
var EffectiveMass : Real

Error : real

The error of the constraint. This should typically be set via the SetError function.
var Error : Real

Gamma : real

Gamma is used to soften constraints. This should typically never be manually set. Instead, it is set when configuring the constraint to act like a spring.
var Gamma : Real

Impulse : real

The total accumulated impulse of this constraint. If you want to not use warm-starting then clear this value every frame.
var Impulse : Real

Linear0 : real3

Linear portion of objectA's Jacobian.
var Linear0 : Real3

Linear1 : real3

Linear portion of objectB's Jacobian.
var Linear1 : Real3

MaxImpulse : real

The max impulse magnitude allowed for the constraint.
var MaxImpulse : Real

MinImpulse : real

The min impulse magnitude allowed for the constraint.
var MinImpulse : Real

Owner : customjoint

read-only

What joint currently owns this constraint.
var Owner : CustomJoint

SolvePosition : boolean

Should this constraint solve position directly or use baumgarte correction? Toggling SolvePosition should be done before setting any other values (ideally in initialization). Setting a constraint to be a motor or a spring will turn off position correction as an error bias must be used to solve those scenarios.
var SolvePosition : Boolean

Methods

ComputeMotor : Void

Sets this constraint as a motor (i.e. a constraint that drives movement along the Jacobian direction at a certain speed). The motor has a min and max impulse value that can be solved (typically -value, +value). If you set this as a motor, you should do so last. Motors should typically be their own constraint unlike springs. |Name|Type|Description| |---|---|---| |targetSpeed|real| | |minImpulse|real| | |maxImpulse|real| |
function ComputeMotor(targetSpeed : Real, minImpulse : Real, maxImpulse : Real)

ComputeSpring : Void

Given the currently set mass and error, fix the constraint to be soft (i.e. solve the constraint like a spring). The spring fixes the constraint using the given frequency (oscillations per second) and damping ratio (0 is no damping, 1 is critical damping). |Name|Type|Description| |---|---|---| |frequencyHz|real| | |dampRatio|real| |
function ComputeSpring(frequencyHz : Real, dampRatio : Real)

DetachFromOwner : Void

Remove this constraint from whatever joint owns it. This is equivalent to "this.Owner.RemoveConstraint(this)". |Name|Type|Description| |---|---|---|
function DetachFromOwner()

IsOwned : boolean

Is this constraint currently owned by a joint? (Equivalent to "this.Owner != null"). |Name|Type|Description| |---|---|---|
function IsOwned() : Boolean

SetErrorAndBias : Void

Set the position error of the constraint. This also sets the bias of the constraint (used to actually correct the error). If you want to set this constraint as a motor you should not call this function (or call it first). If you want to set this as a spring then make sure you call this first. |Name|Type|Description| |---|---|---| |error|real| |
function SetErrorAndBias(error : Real)

SetJacobian : Void

Set the Jacobian of this constraint (and the effective mass). |Name|Type|Description| |---|---|---| |linear0|real3| | |angular0|real3| | |linear1|real3| | |angular1|real3| |
function SetJacobian(linear0 : Real3, angular0 : Real3, linear1 : Real3, angular1 : Real3)

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