Bone Driven Controller

With the Bone Driven Controller Animation Blueprint node, you can dynamically affect the motion of a Target Object, such as another Bone, Morph Target or Material Parameter.

Overview

With this node, you can apply motion data from the Source Bone to dynamically adjust another object on the Skeletal Mesh, such as a character's accessory object, to avoid geometry intersections during an animation.

Here the character's arm bone has been selected as the Source Bone, and the shoulder pad bone has been selected as the destination Target Bone. As the arm rotates, the Bone Driven Controller node uses the arm bone motion to drive a similar rotation of the shoulder pad bone, to avoid the geometry intersection when no motion occurs on the shoulder pad bone.

Set Up

The Bone Driven Controller node operates within Component Space, so a space conversion will need to occur to implement the node within your character's Animation Blueprint.

With the Alpha property or pin, you can control the degree of the applied driven motion on the generated output pose. A value of 1 will fully use the generated output pose, while a value of 0 will output the source pose.

In the Detail panel of the Bone Driven Controller node, you first declare the Source Bone. Then in the Source Component Property, you can select the kind of motion (Translation, Rotation or Scale), and on what axis (X, Y or Z) you want to use from the Source Bone as the motion to drive the target object's motion.

With the Multiplier property you can declare a set value with which to multiply the Source Bone motion as it drives the target object.

If the Multiplier property is a value of 0, no motion will occur. The Multiplier property is ignored when a Driving Curve is selected.

You can assign a curve to modify the Source Bone motion within the Driving Curve property. Curves can provide more precise control over how the Source Bone's motion data is used to drive the target object.

If the Destination Mode property is set to Bone, an applied motion type must be defined. You can define how the Source Bone motion drives the Target Bone, by toggling the different axis of motion in the Translation, Rotation and Scale properties. You can enable any combination of these properties, and the source bone motion data will be applied to each additively.

If there are no applied motion types selected, no motion will occur.

Debug

When a Bone Driven Controller node is selected in the AnimGraph, a debug object will be drawn in the Viewport window to indicate the associated objects. A blue line will be drawn connecting the Source Bone to the target object, and a green cone will be drawn on the blue line pointed in the direction of the target object.

Property Reference

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