Swallowtail

A classic curve from Catastrophy theory. Parametric form:


     x= u*pow(v,2) + 3*pow(v,4) 

     y= -2*u*v - 4*pow(v,3)     

     z= u

Example:

u={-2,2},v={-0.8,0.8}

Here is the PoV3-source I used
And you need the paraloop.inc include file.