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

Property | Description |
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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

Property | Description |
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Disable Collision | This disables collision between the constrained components. |
Enable Lenear Projection | Linear Projection is a post-solve fixup where the child body is translated to resolve remaining errors using a semi-physical correction. Use this to make chains stiffer at lower iteration counts. Projection only works well if the chain is not interacting with other objects. |
Enable Angular Projection | Angular Projection is a post-solve fixup where the child body is rotated to resolve remaining errors using a semi-physical correction. Use this to make chains stiffer at lower iteration counts. Projection only works well if the chain is not interacting with other objects. |
Enable Shock Propagation | Shock Propagation increases the mass of the parent body for the last iteration of the position and velocity solve phases. It can help stiffen up joint chains, but is prone to introduce energy down the chain. Use this for world constraints and ragdoll physics. |
Projection Linear Alpha | The amount of linear projection to apply, with 0 being no projection and 1 being full projection. |
Projection Angular Alpha | The amount of angular projection to apply, with 0 being no projection and 1 being full projection. |
Shock Propagation Alpha | The amount of shock propagation to apply, with 0 being no propagation and 1 being full propagation. |
Parent Dominantes | When set, the parent body in a constraint will not be affected by the motion of the child. |
Linear Limits

Property | Description | ||||||||
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XMotion | Indicates the linear constraint applied along the X-axis.
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YMotion | Indicates the linear constraint applied along the Y-axis.
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ZMotion | Indicates the linear constraint applied along the Z-axis.
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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

Property | Description |
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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. |
Linear Breakable | Whether it is possible to break the joint with linear force. |
Linear Break Threshold | Force needed to break the distance constraint. |
Linear Plasticity | Whether it is possible to reset spring rest length from the linear deformation. |
Linear Plasticity Type | Whether linear placticity has a operation mode. |
Linear Plasticity Threshold | Percent threshold from center of mass distance needed to reset the linear drive position target.This value can be greater than 1. |
Contact Transfer Scale | Collision transfer on parent from the joints child. The maximum range is 0.0. |
Angular Limits

Property | Description | ||||||||
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Swing 1Motion | Indicates whether the Swing1 limit is used.
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Swing 2Motion | Indicates whether the Swing2 limit is used.
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Twist Motion | Indicates whether the Twist limit is used.
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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. |
Advanced

Property | Description |
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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. |
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. |
Angular Breakable | Whether it is possible to break the joint with angular force. |
Angular Break Threshold | Torque needed to break the joint. |
Angular Placticity | Whether it is possible to reset rotations from the angular displacement. |
Angular Placticity Threshold | Degree threshold from target angle needed to reset the target angle. |
Linear Motor

Property | Description |
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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

Property | Description |
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Max Force | The force limit of the drive. |
Angular Motor

Property | Description | ||||||
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Angular Drive Mode | Whether this angular motor uses SLERP (Spherical Linear Interpolation) or decomposes into a Swing Motor and a Twist Motor (cone and roll constraints). SLERP will not work if any of the angular constraints are locked.
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Target Orientation | Target orientation 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. | ||||||
Strength | The force applied to reach the target velocity. |
Advanced

Property | Description |
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Max Force | The force limit of the drive. |