345c7b144d
This is an important hair interaction feature that simulates friction between hairs in an efficient way. The method is based on the paper "Volumetric Methods for Simulation and Rendering of Hair" ( http://graphics.pixar.com/library/Hair/paper.pdf ) It was partially implemented already, but didn't work in this simplified version. The same voxel structure can be used for implemeting repelling forces on hair based on density, which can help a hair system maintain volume instead of collapsing in on itself.