A 'crumpled' cylinder defined by means of three bidimensional fields [Un cylindre 'froissé' défini à l'aide de trois champs bidimensionnels].

                    X = Fx(u,v)

                    Y = Fy(u,v)

                    Z = Fz(u,v)

                    u ∈ [Umin,Umax]

                    v ∈ [Vmin,Vmax]

                       v ^
                         |
                    V    |...... ---------------------------
                     max |      |+++++++++++++++++++++++++++|
                         |      |+++++++++++++++++++++++++++|
                         |      |+++++++++++++++++++++++++++|
                         |      |+++++++++++++++++++++++++++|
                         |      |+++++++++++++++++++++++++++|
                         |      |+++++++++++++++++++++++++++|
                         |      |+++++++++++++++++++++++++++|
                         |      |+++++++++++++++++++++++++++|
                         |      |+++++++++++++++++++++++++++|
                    V    |...... ---------------------------
                     min |      :                           :
                         |      :                           :
                         O------------------------------------------------->
                                U                           U              u
                                 min                         max

                    X = Mx(i,j)

                    Y = My(i,j)

                    Z = Mz(i,j)

                    i = f(u,Umin,Umax,Nu)

                    j = g(v,Vmin,Vmax,Nv)

• Fx = R.cos(v) + fractalX(u,v)
• Fy = R.sin(v) + fractalY(u,v)
• Fz = u

See the perfect cylinder.