: For complex characters, these controls can be added to a Character Extension (like a "Tail" extension) to ensure they are properly recognized and baked with the rest of the control rig. Best Use Cases
Under the tab, enter a value for the Number of control nodes . MotionBuilder will automatically create evenly spaced nodes along the skeleton chain. Motionbuilder Tutorial - 18: Spline IK
: Ensure your joint chain is exactly perpendicular to the Y-axis ; otherwise, the constraint cannot be initialized. Apply the Constraint : Select the bones in your scene. : For complex characters, these controls can be
In MotionBuilder Tutorial - 18: Spline IK , you will learn how to use to animate flexible, multi-joint structures like tails, tentacles, and ropes . This specialized constraint aligns a skeleton joint chain along a curve, providing a smoother and more predictable way to achieve complex, aesthetically pleasing shapes than traditional FK or IK rigs. Core Workflow for Spline IK : Ensure your joint chain is exactly perpendicular
Enable and click Snap to activate the constraint and bind the bones to the curve. Advanced Control Features
In the , drag the starting bone into the First Joint field and the final bone into the End Joint field. Create Control Nodes :
Drag the from the Asset Browser’s Constraints folder into the viewport. Define the Chain :