Hair should have stiffness while combing

Combing hair currently creates unrealistic kinks very easily and also tends to mash hair into the originating mesh in blatant disregard for reality in which two objects cannot occupy the same space.

While self-collision is probably computationally too intensive to be practical, three things would go a long way toward making hair/fur easier to position by combing:

• Hair should have some stiffness, a la cloth springs, so that it doesn't kink.
• Hair roots in particular should have an option to limit how far from surface-normal they can be. This should possibly be separate from overall stiffness. This would help keep hair from lying flat on (or in ) the associated surface.
• Hair should be repelled from the originating surface, preferably in proportion to the spline position (i.e. the repulsion distance is greater at the tip than near the root). This would help hair to "layer" more naturally.