Spring Property Editor
 
 
 

| Constraint | Attachment

Sets the options for the spring constraint (a spring-like shaft) to determine its behavior in a rigid body simulation. The spring constraint is based on Hooke's law which states that the force a spring exerts is directly proportional to how much it extends (its length).

To create a spring constraint: Choose Create Rigid Body Rigid Constraint or Multi Constraint Tool Spring from the Simulate menu. Then pick the location for the constraint object and the rigid bodies to be constrained.

To redisplay this property editor: Select the spring constraint object and press Enter.

For more information in general, see Types of Rigid Body Constraints [ Simulation].

Constraint

Active

Toggles the activeness of the constraint. Deselect this option to mute the constraint, which prevents it from affecting the simulation.

Visible

Toggles the display of the constraint object in a view.

Attached Bodies Intercollide

Toggles the collision state of rigid bodies that are attached together by this constraint. For example, if you don't want a forearm to collide with a biceps, deselect this option.

Parameters

Spring (Kp)

The constant that determines the strength of the spring (the spring coefficient in Hooke's law). Kp is multiplied by the extension of the spring (beyond its rest length) to determine the force exerted on each rigid body. The units are based on Newtons per meter.

Damping (Kd)

Reduces the velocity of the constrained object. Kd is the damping coefficient, which is multiplied by the rigid bodies' mutual velocity to determine the damping force (which acts in the opposite direction as the Spring). The units are in Newtons per meter per second.

Rest Length (R)

The length in Softimage units to which the spring tries to return during the simulation.

Feedback

These parameters are for informational purpose only: you cannot modify them.

Attachment

These parameters allow you to offset the position of the spring's attachment points on either constrained rigid body.

These parameters are available only if you are using the PhysX dynamics engine.

For more information, see Offsetting Spring and Slider Constraints [ Simulation].

Body A - Local Offset

Using the X/Y/X sliders, offset the position of spring's attachment point to the Body A rigid body while remaining anchored to the Body B rigid body. Body A is the first rigid body that you picked when you created the spring constraint.

Body B - Local Offset

Using the X/Y/X sliders, offset the position of spring's attachment point to the Body B rigid body while remaining anchored to the Body A rigid body. Body B is the second rigid body that you picked when you created the spring constraint.