If you are animating your scenes, you can create more natural looking fur by making it react to movement and forces. For example, when an animal shakes its fur, the fur does not typically stay in one place (unless it is very short)—it reacts to the movement of the body. Similarly, long fur blows around on a windy day.

To style fur and create realistic dynamic fur simulations, you use hair curves, which are connected to the Fur description. These curves can be of any length or shape. They can be either static (for styling) or dynamic. Use dynamic hair curves when you want to make fur react to dynamic forces. For example, you can set up the fur on a dog so that when it shakes itself, the fur reacts appropriately.

To modify the look of Fur, use the Fur Description attributes; to edit the dynamic behavior of the Fur, use the attributes in the attached hairSystem node.

The basic workflow for adding movement to fur is as follows

1. Add fur to the surface. For details, see Create fur.
2. Create a hair system to be used with Fur using either static or dynamic curves. For details, see Create a hair system to be used with fur.
3. Attach the hair system to the fur description. See To attach an existing hair system to a Fur description.

   A furCurveAttractor set is created.

4. Modify attractor set attributes. For details, see FurCurveAttractors node.
5. Animate the movement of the fur curve attractors by doing one of the following:
   • Manually keyframe static hair start curves.
   • Play the dynamic hair curve simulation and adjust the dynamic behavior of the fur by modifying the attributes in the hairSystem node or the follicleShape node/Channel Box.
6. Render the frames that make up the animation. For details, see Render an animation with fur.
   NoteIf your fur doesn’t move during the simulation, check to make sure the multiple of the Global Scale and Threshold Length values (FurCurveAttractors node) does not exceed the Length value (FurDescription node). When it does, fur is not influenced by curve attractors. For example:

   Threshold Length (0.33) * Global Scale (10) = 3.33

   Length of the fur description = 1.5 < 3.3 so the fur is not influenced by curve attractors.