In the previous post hair was animated with bones. This works well if the hair only has few degrees of freedom, like a pony-tail. However, for long, loose hair it becomes very tedious to animate the hair by hand. It would be much simpler to do a cloth simulation, but we all know that this becomes extremely slow for high-poly meshes.
In version 2.79, Blender has a new Surface Deform modifier, which can be used to speed up hair simulation. I created a low-poly hair guide and made a cloth simulation for it. The simulation is fast because the guide is a low-poly mesh. The animation was then transferred to the high-poly hair mesh using the surface deform modifier. The modifier is a bit picky; it does not work if the guide mesh contains concave faces, and the hair tends to develop spikes unless the guide is very smooth. By splitting the faces to triangles and smoothing the mesh I managed to get rid of the most glaring problems.
Here is a video that shows my take on it.