Patent ID: 7418371

Claim:
A method for graphical hairstyle generation comprising steps of: a) generating hair strands and wisps by controlling the statistical properties of hair using a statistical wisp model; b) solving the hair deformation due to gravity and collisions between the hair by a pseudo-physical approaches using a styling force field; c) styling the hair by superimposing a constraint force field with the styling force field and solving the hair deformation; and d) drawing the hair strands using probability density functions to represent the randomness of hair color, wherein the step of generating hair strands and wisps comprises steps of: modeling first hair strands using an example-based Markov chain model from a given prototype strand; and duplicating the first hair strands to the neighboring second hair strands by creating statistically-controlled variations, wherein the hair strand is represented as a Catmull-Rom spline, wherein the Catmull-Rom spline is defined and passes through a sequence of control points {p 1 , p 2 , . . . p n }, wherein the spline p(s) is parameterized within the range [0,1], wherein p(0)=p 1 and p(1)=p n correspond to the root and the tip of the strand respectively, wherein the overall shape of the wisp is a generalized cylinder and the hair strands within the wisp have a similarity, wherein the degree of similarity of the strands within a wisp is controlled by a length distribution, a deviation radius function, and a strand-shape fuzziness value, wherein the length distribution l(u) is probability density function that gives the probability that a member strand will have length u, relative to the length of the master strand, wherein the deviation radius function r(s) specifies an upper limit on the positional offset of the member strands from the master strand at the parameter value s and controls the shape of the generalized cylinder representing the wisp, wherein the strand-shape fuzziness value σ controls the variation of the strands within a wisp.