This is a quick and simple formula modification of the pillow script modification of Michaels LineWeb script.
Included is a "Half" version, which restricts the range of v curve to 0 - pi. Preliminary attempts to add a selection button for "full" and "half" were unsuccessful,
due to poor understanding of htm. I'm sure it is actually very simple...
Don't know what this surface is good for...

It'"s good for that ;)
French "Berlingots" (sugar kandies)

Pilou, c'est le bonbon - ici un "berlingot de Carpentras" -
qui prend le nom de la forme, pas le contraire;
le mot berlingot désignant la forme de thétraèdre.
(fin de la disgression ;^) )

...et ce n'est pas bon pour les caries non plus! :D