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Physics Constraint Reference

This page contains a reference listing of properties for Physics Constraints separated by major category.

Constraint

propConstraint.png

Property Description
Constraint Actor 1 When a Physics Constraint is placed into the level editor you must specify Actors to constrain. This is the first of 2 Actors.
Component Name 1 The first target component that will be constrained. This can be specified when using Actors to constrain only a specific component and not the Actor root.
Constraint Actor 2 When a Physics Constraint is placed into the level editor you must specify Actors to constrain. This is the second of 2 Actors.
Component Name 2 The second target component that will be constrained. This can be specified when using Actors to constrain only a specific component and not the Actor root.
Joint Name When constraining in the Physics Asset Tool, this is the name of the Bone that is initially constrained.
Constraint Bone 1 When constraining in the Physics Asset Tool, this is the name of the first joint to constrain.
Constraint Bone 2 When constraining in the Physics Asset Tool, this is the name of the second joint to constrain.

Constraint Behavior

propProjection.png

Property Description
Disable Collision This disables collision between the constrained components.
Enable Projection If the distance error between bodies exceeds Projection Linear Tolerance value, or rotational error exceeds Projection Angular Tolerance, the Physics Body will be projected to fix this. This fixes cases where the visuals look disconnected, such as individual chain links breaking away from each other.
Projection Linear Tolerance If the distance error exceeds this value, in world units, the body will be projected.
Projection Angular Tolerance If the rotational error exceeds this value, in degrees, the body will be projected.

Linear Limits

propLinearLimits.png

Property Description
XMotion Indicates the linear constraint applied along the X-axis.
Type Description
Free No constraint along this axis.
Limited Limited freedom along this axis. The limit is defined for all axes by the Linear Limit Size property.
Locked Fully constraint along this axis.
YMotion Indicates the linear constraint applied along the Y-axis.
Type Description
Free No constraint along this axis.
Limited Limited freedom along this axis. The limit is defined for all axes by the Linear Limit Size property.
Locked Fully constraint along this axis.
ZMotion Indicates the linear constraint applied along the Z-axis.
Type Description
Free No constraint along this axis.
Limited Limited freedom along this axis. The limit is defined for all axes by the Linear Limit Size property.
Locked Fully constraint along this axis.
Limit The distance allowed between the two joint reference frames.
Scale Linear Limits If true, linear limits scale using the absolute min of the 3D scale of the owning component.

Advanced

propLinearLimitsADV.png

Property Description
Soft Constraint Whether we want to use a soft constraint (spring).
Stiffness Stiffness of the soft constraint. Only used when Soft Constraint is on.
Damping Damping of the soft constraint.
Restitution Controls the amount of bounce when the constraint is violated.
Contact Distance Determines how close to the limit we have to get before turning the joint on.
Linear Breakable Whether it is possible to break the joint with linear force.
Linear Break Threshold Force needed to break the distance constraint.

Angular Limits

propsAngularLimits.png

Property Description
Swing 1Motion Indicates whether the Swing1 limit is used.
Type Description
Free No constraint around this axis.
Limited Limited freedom around this axis. The limit for each Angular Motion is controlled individually by a correspondingly named Limit property: Swing 1Limit Angle, Swing 2Limit Angle, and Twist Limit Angle.
Locked Fully constraint around this axis.
Swing 2Motion Indicates whether the Swing2 limit is used.
Type Description
Free No constraint around this axis.
Limited Limited freedom around this axis. The limit for each Angular Motion is controlled individually by a correspondingly named Limit property: Swing 1Limit Angle, Swing 2Limit Angle, and Twist Limit Angle.
Locked Fully constraint around this axis.
Twist Motion Indicates whether the Twist limit is used.
Type Description
Free No constraint around this axis.
Limited Limited freedom around this axis. The limit for each Angular Motion is controlled individually by a correspondingly named Limit property: Swing 1Limit Angle, Swing 2Limit Angle, and Twist Limit Angle.
Locked Fully constraint around this axis.
Swing 1Limit Angle Angle of movement along the XY Plane.
Twist Limit Angle Angle of movement along the XZ Plane.
Swing 2Limit Angle Symmetric angle of roll along the X-axis.
Angular Rotation Offset Specifies the angular offset between the two frames of reference. By default this limit goes from (-Angle, +Angle).

Advanced

propsAngularLimitsADV.png

Property Description

Swing Limits

Soft Constraint Whether we want to use a soft constraint (spring).
Stiffness Stiffness of the soft constraint. Only used when Soft Constraint is on.
Damping Damping of the soft constraint.
Restitution Controls the amount of bounce when the constraint is violated.
Contact Distance Determines how close to the limit we have to get before turning the joint on.

Twist Limits

Soft Constraint Whether we want to use a soft constraint (spring).
Stiffness Stiffness of the soft constraint. Only used when Soft Constraint is on.
Damping Damping of the soft constraint.
Restitution Controls the amount of bounce when the constraint is violated.
Contact Distance Determines how close to the limit we have to get before turning the joint on.

Breakable

Angular Breakable Whether it is possible to break the joint with angular force.
Angular Break Threshold Torque needed to break the joint.

Linear Motor

propLinearMotor.png

Property Description
Position Target Enables the position linear motor on one or more axes and sets the local position desired.
Strength How much force to apply to reach the desired position.
Velocity Target Enables the velocity linear motor on one or more axes and sets the desired velocity.
Strength How much force to apply to reach the desired velocity.

Advanced

PhysCon_MotorADV.png

Property Description
Max Force The force limit of the drive.

Angular Motor

propsAngularMotor.png

Property Description
Angular Drive Mode

Whether this angular motor uses SLERP (Sphereical Linear Interpolation) or decompose into a Swing Motor and a Twist Motor (cone and roll constraints). SLERP will not work if any of the angular constraints are locked.

Property Description
SLERP Sets the motor to SLERP (Sphereical Linear Interpolation) mode. SLERP mode will not work if any of axis of the angular constraint is locked.
Twist and Swing Sets the motor to Twist and Swing (cone and roll constraints) mode.
Target Orientation Target proemtatopm relative to the body reference frame.
Drives Depending on the Angular Drive Mode setting, you can enable or disable the different motors for that mode.
Strength The force applied to reach the target orientation.
Target Velocity Target angular velocity relative to the body reference frame
Drives Depending on the Angular Drive Mode setting, you can enable or disable the different motors for that mode.
Stength The force applied to reach the target velocity.

Advanced

PhysCon_MotorADV.png

Property Description
Max Force The force limit of the drive.
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