regression with draw3d ?



Hello,

The following works in Maxima 5.27.0.1 on Windows, and fails with Maxima 
5.28 (nothing happens).

load(draw)$
draw3d(xu_grid = 30, yv_grid = 60, surface_hide = true,
    parametric_surface(cos(phi) * sin(theta),
                       sin(phi) * sin(theta),
                       cos(theta),
                       theta, 0, %pi, phi, 0, 2 * %pi))$