Blender Git Commit Log

Another curve mapping to control bending stiffness along hair strands.

This already exists for goal springs. Bending stiffness, however, is
preferable to global goal springs for physical realism. Controlling
stiffness in this way allows using bending forces to also simulate
unconventional hair, such as clumpy strands that are thicker and stiffer
at the base.

Note that hair interaction can also be simulated with this tool in some
way, although eventually better methods may be needed for such effects.