isosurface
// create a isosurface object - the equipotential surface
// of a 3D math function f(x, y, z)
#declare fn_X = function(x,y,z) { x*x + y*y - 1 } // cylinder function
isosurface {
function { x*x + y*y - 1 } // function (can also contain declared functions
//function { fn_X(x, y, z) } // alternative declared function
contained_by { box { -1.2, 1.2 } } // container shape
//threshold 0.0 // optional threshold value for isosurface [0.0]
accuracy 0.001 // accuracy of calculation [0.001]
max_gradient 4 // maximum gradient the function can have [1.1]
//evaluate 5, 1.2, 0.95 // evaluate the maximum gradient
//max_trace 1 // maybe increase for use in CSG [1]
//all_intersections // alternative to 'max_trace'
//open // remove visible container surface
}