Spring Operator Property Editor
 
 
 

| Spring | State

Determines the behavior of the spring for a tail, ear, or belly control object in a rig.

To display: Select a tail object (Create Skeleton Make Tail), or a tail, ear, or belly control object in a biped, dog leg biped, or quadruped rig (Create Character Rig).

In the explorer, expand the Kinematics Global Transformation node for the control object's end effector (which is hidden) and click the Spring operator icon.

For more information, see Spring Operators for Tail, Ear, and Belly Rig Controls [ Character Animation ].

Spring

Type

Sets the spring to use either Linear or Angular forces. Linear springs apply a linear force to the simulated object, whereas an angular spring applies a twisting force or torque.

Mute Simulation

Toggles the activeness of the spring's simulation.

This parameter has an expression on it that links it to the state of the control object's Mute parameter.

Reset Simulation

Resets the spring to its rest position.

Mass

Mass in kilograms (kg) of the spring. The more mass, the more force it takes to change the spring's direction.

Scale

Size of the control object's spring relative to the distance unit used by the simulator. The simulator uses meters for distance while Softimage uses grid units, so this value is the number of grid units per meter. A scale value of 2 means if the simulation moves an object 1 meter, the object will move 2 grid units in Softimage. You should set this value to keep the spring's behavior the same when scaling rigs: if the rig is doubled in size, the spring's scale needs to be doubled as well to maintain the same effect.

Stiffness

Sets the rigidity of the spring. Higher values cause the spring to be stiffer.

Damping

Sets the resistance of the spring to velocity and affects how quickly it responds to movement or animation.

Low damping values make the spring respond quickly to animation, but it can be bouncy and may oscillate before reaching its animated (rest) state. High damping values make the spring respond more slowly to animation and move smoothly to its animated (rest) state.

Step Size

Size of each evaluation step of the simulation. This parameter has an expression on it that makes it equal to the tail control object's Response Speed value. Be careful about using too high a step size value because it may make the simulation unstable.

Sub Steps

The number of times that the spring simulation is evaluated at each frame. For example, at 30 frames per second, setting this value to 4 would mean that the simulation is updated 120 times a second.

Increasing this value can make the simulation more accurate, especially with fast-moving objects. Of course, increasing this value also increases the calculation time of the simulation. You should start with a low level and gradually work up in small increments. You shouldn't usually need more than a value of 100 or less than a value of 4.

State

Current State

Set as Initial State

Sets the spring's current state to be its initial state. This changes the spring's Initial StatePosition and Velocity values to determine the position and velocity of the spring at the start of the simulation.

Set as Rest Pos

Set the spring's current state to be its rest state. This changes the spring's Rest StatePosition values to determine the position of the spring in its resting state (pose as unaffected by simulation).

Rest State

Position X/Y/Z

Sets the position in X/Y/Z of the spring in its resting state (pose unaffected by simulation).

Initial State

Position X/Y/Z

Sets the position in X/Y/Z of the spring at the start of the simulation (initial pose).

Velocity X/Y/Z

Sets the velocity in X/Y/Z of the spring at the start of the simulation (initial pose).