parametric
// parametric object
// not yet worked out
parametric {
function { u*v*sin (15*v) }, // x-axis
function { v }, // y-axis
function { u*v*cos (15*v) } // z-axis
<0,0>, <1,1>
// contained_by { sphere { 0,1 } } // texturing problem, use box instead to see!
contained_by { box { <-1,-1,-1>, <1,1,1> } }
// max_gradient 2
accuracy 0.005 // 0.001 default, lower slower but better
precompute 15 x,y,z // precompute [x,y,z] normally gives faster rendering (<=20)
rotate 180*x
}