Sinus Displacement

The Sinus Displacement modifier adds a sinusoidal displacement to the stroke.

Wavelength
How wide the undulations are along the stroke.
Amplitude
How high the undulations are across the stroke.
Phase
Allows «offsetting» («moving») the undulations along the stroke.
../../../../../../_images/render_freestyle_parameter-editor_line-style_modifiers_geometry_sinus-displacement-example.png

Sinus Displacement modifier demo by T.K. (blend-file).