63   vtkSetClampMacro(Angle,
double,0.0,89.0);
 
   64   vtkGetMacro(Angle,
double);
 
abstract interface for implicit functions 
virtual double EvaluateFunction(double x[3])=0
implicit function for a cone 
double EvaluateFunction(double x, double y, double z)
virtual void EvaluateGradient(double x[3], double g[3])=0
a simple class to control print indentation 
void PrintSelf(ostream &os, vtkIndent indent)
#define VTKCOMMONDATAMODEL_EXPORT