Hair Dynamics, Deformations, and Styling
Dynamics allows the hair to be affected by the movement of the hair emitter object and natural forces. You can also use dynamics as a styling tool by freezing the hair when it’s at a state that you like. For example, apply dynamics, apply some wind to the hair, then freeze the hair when it has the right wind-swept look.
Remember that if you have applied dynamics to the hair, you cannot use the style operators on the hair unless you mute the dynamics operator by clicking the Style button on the Hair toolbar.
Using Deformations as Styling Tools
Besides using dynamics to style hair, you can use all of the standard XSI deformation operators on hair to come up with some groovy hairdos! This includes all the operators in the Deform menu on the Model, Animate, and Simulate toolbars. In addition to these operators, you may want to use lattices, envelopes, deform by cluster center, randomize, and deform by volume to produce the most favorable results.
Remember that if you animate the deformations, you cannot then use dynamics on the hair.
As well, you can use obstacle collisions (with or without having dynamics active) to mold the hair around the obstacle to style it, then freeze it to keep the state you want.
Using Syflex Cloth to Deform Hair
Another alternative to using dynamics for styling hair is to use the Syflex cloth sytem. To do this, create the hair, then create a grid and make it a cage deformer. Then add Syflex cloth to the grid to make it move. It's important to apply these operators in this order: if your grid has already Syflex applied to it, it will not work. Once applied, move the cage deformer into the Shape Modeling region in the construction history.
Note: Guide hairs are effectively IK chains, and deforming them can cause them to kink. To prevent this, activate the Stretchy button on the Hair toolbar to have hair stretch with the deformation, and try to avoid deformations that overly stretch the hair.