Spring Controller

Describes the Spring Controller which is used to limit how far a bone can stretch from its reference pose before force is applied in the opposite direction.

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With the Spring Controller Animation Blueprint node, you can apply a controlled stretch to bone from a character's skeleton.

spring controller animation blueprint node

Here is an example of the Spring Controller node being used to simulate movement of non-animated bones by applying a force in the opposite direction for the character's motion.

spring cotroller demo disabled

spring controller demo enabled

Spring Controller Disabled

Spring Controller Enabled

Property Reference

spring controller animation blueprint node details pannel

Here you can reference a list of the Spring Controller node's properties.

Property

Description

Spring Bone

Select the bone from the character's skeleton to apply the Spring Controller node to.

Max Displacement

Set the maximum distance the bone can stretch from the reference pose location, in Unreal Engine units, when Limit Displacement is enabled.

Spring Stiffness

Set a multiplier value used to calculate the stiffness of the spring. Larger values require more bone velocity to displace the bone and result in a larger applied force with quicker reactive movements.

Spring Damping

Set a multiplier to reduce the Spring Bones's velocity, to create smoother and more controlled results.

Error Reset Thresh

Set a threshold to reset the Spring Bones in Unreal Engine units. If the Spring Bone stretches more than this amount, it resets in order to avoid errors introduced by sudden, large displacements such as those caused by teleporting Actors.

Limit Displacement

When enabled the Max Displacement property will be considered.