Patent attributes
A volumetric representation of a hair simulation model determines collective hair attributes. To determine inter-hair collisions, vertices include average velocities of the adjacent portions of the model. The average velocities determine target velocities. Forces for the model are determined from the target velocity values. To direct hair to a desired pose, vertices include target and current density values representing the density of adjacent portions of the model in the desired pose and current position, respectively. The differences in density values determine pressure forces applied to the model. To determine the illumination of the hair, vertices include density values representing the density of adjacent portions of the model. The density values define a hair surface, and signed distance values relative to the surface are determined for the vertices. Normal vectors are determined from the gradients of the signed distance values at locations corresponding the positions of the hairs.