Dynamic spline IK chain illustrated using a butterfly tail

User Guide > Dynamics and Effects > Hair > Samples and techniques for Hair > Sample dynamic curve scenarios >

In this scenario a dynamic spline IK chain is created and used on a dragonfly-type bug model. As the dragon bug moves about, its tail wiggles slightly.

To play the animation, click the link below.

dragonbug.mov

To create a dynamic spline IK chain

Create a new scene and switch to the Side orthographic view.
In the Animation menu set, select Skeleton > Joint Tool.
To draw a tail in a rest position, as shown in the image below, click near the top of the Y-axis and then click to create joints as though they were along the tail. At the last joint press Enter.
Select Create > CV Curve Tool and trace a curve over the joints, clicking at each joint to create a CV. Press Enter at the end of the last joint.
With the curve selected, in the Dynamics menu set, select Hair > Make Selected Curves Dynamic.
Select Hair > Display > Current Position.
To attach the curve into the chain, in the Animation menu set, select Skeleton > IK Spline Handle Tool > .
In the IK Spline Handle Settings editor, turn off Auto Create Curve.
Follow the instructions in the Help Line, which are:
- Click the start joint.
- Click the end joint.
- Click the Current Position curve.
To select the follicle, do the following:
- Select the curve.
- Select the follicleShape in the Attribute Editor.
- Click the Select button at the bottom of the Attribute Editor.
In the follicleShape, set Point Lock to Base.
To play the simulation, select Solvers > Interactive Playback.
To stabilize the dynamic curve’s behavior, adjust the Stiffness value and the number of Iterations in the Dynamics section of the hairSystemShape of the Attribute Editor.