FreeMat
vtkParametricDini

Section: Visualization Toolkit Common Classes

Usage

vtkParametricDini generates Dini's surface. Dini's surface is a surface that posesses constant negative Gaussian curvature

For further information about this surface, please consult the technical description "Parametric surfaces" in http://www.vtk.org/documents.php in the "VTK Technical Documents" section in the VTk.org web pages.

.SECTION Thanks Andrew Maclean a.mac.nosp@m.lean.nosp@m.@cas..nosp@m.edu..nosp@m.au for creating and contributing the class.

To create an instance of class vtkParametricDini, simply invoke its constructor as follows

  obj = vtkParametricDini

Methods

The class vtkParametricDini has several methods that can be used. They are listed below. Note that the documentation is translated automatically from the VTK sources, and may not be completely intelligible. When in doubt, consult the VTK website. In the methods listed below, obj is an instance of the vtkParametricDini class.

  • string = obj.GetClassName ()
  • int = obj.IsA (string name)
  • vtkParametricDini = obj.NewInstance ()
  • vtkParametricDini = obj.SafeDownCast (vtkObject o)
  • int = obj.GetDimension () - Set/Get the scale factor. Default = 1.
  • obj.SetA (double ) - Set/Get the scale factor. Default = 1.
  • double = obj.GetA () - Set/Get the scale factor. Default = 1.
  • obj.SetB (double ) - Set/Get the scale factor. Default = 0.2
  • double = obj.GetB () - Set/Get the scale factor. Default = 0.2
  • obj.Evaluate (double uvw[3], double Pt[3], double Duvw[9]) - Dini's surface.

    This function performs the mapping $f(u,v) \rightarrow (x,y,x)$, returning it as Pt. It also returns the partial derivatives Du and Dv. $Pt = (x, y, z), Du = (dx/du, dy/du, dz/du), Dv = (dx/dv, dy/dv, dz/dv)$ . Then the normal is $N = Du X Dv$ .

  • double = obj.EvaluateScalar (double uvw[3], double Pt[3], double Duvw[9]) - Calculate a user defined scalar using one or all of uvw, Pt, Duvw.

    uvw are the parameters with Pt being the the cartesian point, Duvw are the derivatives of this point with respect to u, v and w. Pt, Duvw are obtained from Evaluate().

    This function is only called if the ScalarMode has the value vtkParametricFunctionSource::SCALAR_FUNCTION_DEFINED

    If the user does not need to calculate a scalar, then the instantiated function should return zero.