A spline IK handle lets you control a joint chain with a NURBS curve. All joints driven by the spline IK handle stay on and follow the curve. The spline IK handle gives you additional attributes, such as twist, for additional control over the orientation of the joints in your joint chain. See ikHandle.

To create a spline IK handle and automatically create the spline IK NURBS curves

1. Select your joint chain.
2. In the Animation menu set (press F2), select Skeleton > IK Spline Handle Tool > .

   The IK Spline Handle Tool settings panel appears.

3. Turn on Auto Create Curve.

   See Auto Create Curve.

4. Select a Number of Spans for the spline IK curve.

   See Number of Spans.

5. Click the start joint for the spline IK handle.
6. Click the end joint for the spline IK handle.

   The spline IK handle and a NURBS curve appears on the joint chain.

To create a spline IK handle using a pre-existing NURBS curve

1. Draw a NURBS curve along the path of the joint chain.

   Create a simple curve with no sharp bends to ensure the joint chain moves smoothly when you animate the curve.

   If you create a curve with few CVs, your control of the curve’s shape and skeleton’s movement will be less precise, but you’ll be able to manipulate the curve and its joint chain more easily.

   For more information see, Components of NURBS curves in the Background chapter of the NURBS Modeling guide.

2. Select your joint chain.
3. In the Animation menu set (press F2), select Skeleton > IK Spline Handle Tool > .

   The IK Spline Handle Tool settings panel appears.

4. Turn off Auto Create Curve.

   See Auto Create Curve.

5. Click the start joint for the spline IK handle.
6. Click the end joint for the spline IK handle.
7. Select the NURBS curve.

   The spline IK handle appears on the joint chain. The joints in the chain rotate to follow the shape of the curve.