Paraboloid and Hyperboloid from the include file "shapes.inc"

Paraboloids, in positive x direction)
Paraboloid_X,	Hyperboloid     (sadle, see left)
Paraboloid_Y	Hyperboloid_Y
Paraboloid_Z	(double cone in y direction, see in tne middle, and right turned by rotate<90,0,0>}

These are infinite surfaces which can be used in csg functions like "intersection" or "clipped_by" with finite shapes to get finite shapes of these kinds.
These regular geometric shapes are defined symetric to <0,0,0>. Sample for how to use them as "object" by:

object{ Paraboloid_Y texture{....} translate<...> }