Noise

Use this modifier to add three-dimensional noise to spline primitives. For example, you can use Noise to generate small waves through grass or hair.

Noise Modifier

Mask: Controls the strength of the modifier effect. You can use Mask to load a map that specifies how areas of the mesh surface are affected by the modifier.
Frequency: Sets the frequency of the noise as cycles per-unit length of the primitive.
Magnitude: Sets the maximum distance that CVs can be displaced by the effect to the Noise Modifier.
Magnitude Scale: Lets you scale the magnitude of the Noise effect each point along the primitive
Correlation: Sets the amount that the effect of noise correlates between neighboring primitives.
Preserve Length: Sets the percent (0 to 100) to blend the modified primitive length to original groomed primitive length.

Mode: Specifies what you want to do with the Modifier effect generated in the scene.
Live: Applies the Modifier effect directly to the primitive. Use this option if you want to edit the effect further.
Baked: Saves the modified primitives to an XPD file, which can be read when previewing or rendering. Use this option if you do want to edit the effect.
Bake Dir: Specifies the directory in which you want to save the XPD file.

Click Bake Data to save the XPD file. See for XGen files for information about XPD files.