The surface normal will usually be directed outward, but may be directed inward by giving negative values for both radii. (It is illegal for the signs of the two radii to disagree.)\0 One but not both radii may be zero, indicating that the cone comes to a point.
Although it is not strictly forbidden to have equal cone radii, the cyl entity should be used in such cases. Likewise, the ring entity must be used if v1 and v2 are equal.
# A parasol o parasol v v1 = p 0 0 0 v v2 = p 0 0 .75 v v3 = p 0 0 .7 m handle_mat cyl v1 .002 v2 m parasol_paper cyl v2 0 v3 .33 o