The invention relates to a method of generating a synthesized image of a hair, comprising the following steps: calculating the shape of the hair by applying a behavioral relationship determining the shape of the hair as a function of a physical parameter linked to a mechanical property of the hair, in particular the linear density; producing an image of the hair of shape that has been calculated in this way. The behavioral relationship may be given by the minimization of the following function: E = K L ⁢ ∫ 0 1 ⁢ [ 1 2 ⁢ ( k ~ ⁡ ( s ~ ) - α ) 2 + 1 β ⁢ z ~ ⁡ ( s ~ ) ] ⁢ ⁢ ⅆ s ~ , where α=Lk0 and β=K/gμL3, and where L designates the length of the hair, k0 its spontaneous curvature, K its bending moment, μ its linear density and g the acceleration due to gravity, {tilde over (s)} the curvilinear abscissa relative to the length of the hair, {tilde over (k)} its local curvature relative to its length and {tilde over (z)} its height relative to its length.