### 2.6.4 Isosurface and Parametric Objects

The new `isosurface` object allows to directly render surfaces defined by an arbitrary mathematical function.

      isosurface {
        function { sqrt( pow(x,2) + pow(y,2) + pow(z,2)) - 1 }
        contained_by { box { -1, 1 } }
      }

generates a simple sphere for example. The surface rendered is an equipotential surface of the specified function. There is a large collection of internal functions available for designing objects. For details see the introductory tutorial or the reference section.

The `parametric` object makes it possible to directly render a surface defined by a set of three parametric functions.