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Usage
vtkParametricFunction is an abstract interface for functions
defined by parametric mapping i.e. f(u,v,w)->(x,y,z) where
u_min <= u < u_max, v_min <= v < v_max, w_min <= w < w_max.
(For notational convenience, we will write f(u)->x and
assume that u means (u,v,w) and x means (x,y,z).)
The interface contains the pure virtual function, Evaluate
(), that generates a point and the derivatives at that point
which are then used to construct the surface. A second pure
virtual function, EvaluateScalar(), can be used to generate
a scalar for the surface. Finally, the GetDimension()
virtual function is used to differentiate 1D, 2D, and 3D
parametric functions. Since this abstract class defines a
pure virtual API, its subclasses must implement the pure
virtual functions GetDimension(), Evaluate() and
EvaluateScalar().
This class has also methods for defining a range of
parametric values (u,v,w).
.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 vtkParametricFunction, simply
invoke its constructor as follows
obj = vtkParametricFunction
Methods
The class vtkParametricFunction 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 vtkParametricFunction class.
* string = obj.GetClassName ()
* int = obj.IsA (string name)
* vtkParametricFunction = obj.NewInstance ()
* vtkParametricFunction = obj.SafeDownCast (vtkObject o)
* int = obj.GetDimension ()
* obj.Evaluate (double uvw[3], double Pt[3], double Duvw[9])
- Performs the mapping $f(uvw)->(Pt,Duvw)$f. This is a
pure virtual function that must be instantiated in a
derived class.
uvw are the parameters, with u corresponding to uvw[0], v
to uvw[1] and w to uvw[2] respectively. Pt is the returned
Cartesian point, Duvw are the derivatives of this point
with respect to u, v and w. Note that the first three
values in Duvw are Du, the next three are Dv, and the
final three are Dw. Du Dv Dw are the partial derivatives
of the function at the point Pt with respect to u, v and w
respectively.
* 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. This is a pure virtual
function that must be instantiated in a derived class.
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().
* obj.SetMinimumU (double ) - Set/Get the minimum u-value.
* double = obj.GetMinimumU () - Set/Get the minimum u-value.
* obj.SetMaximumU (double ) - Set/Get the maximum u-value.
* double = obj.GetMaximumU () - Set/Get the maximum u-value.
* obj.SetMinimumV (double ) - Set/Get the minimum v-value.
* double = obj.GetMinimumV () - Set/Get the minimum v-value.
* obj.SetMaximumV (double ) - Set/Get the maximum v-value.
* double = obj.GetMaximumV () - Set/Get the maximum v-value.
* obj.SetMinimumW (double ) - Set/Get the minimum w-value.
* double = obj.GetMinimumW () - Set/Get the minimum w-value.
* obj.SetMaximumW (double ) - Set/Get the maximum w-value.
* double = obj.GetMaximumW () - Set/Get the maximum w-value.
* obj.SetJoinU (int ) - Set/Get the flag which joins the
first triangle strip to the last one.
* int = obj.GetJoinU () - Set/Get the flag which joins the
first triangle strip to the last one.
* obj.JoinUOn () - Set/Get the flag which joins the first
triangle strip to the last one.
* obj.JoinUOff () - Set/Get the flag which joins the first
triangle strip to the last one.
* obj.SetJoinV (int ) - Set/Get the flag which joins the the
ends of the triangle strips.
* int = obj.GetJoinV () - Set/Get the flag which joins the
the ends of the triangle strips.
* obj.JoinVOn () - Set/Get the flag which joins the the ends
of the triangle strips.
* obj.JoinVOff () - Set/Get the flag which joins the the
ends of the triangle strips.
* obj.SetTwistU (int ) - Set/Get the flag which joins the
first triangle strip to the last one with a twist. JoinU
must also be set if this is set. Used when building some
non-orientable surfaces.
* int = obj.GetTwistU () - Set/Get the flag which joins the
first triangle strip to the last one with a twist. JoinU
must also be set if this is set. Used when building some
non-orientable surfaces.
* obj.TwistUOn () - Set/Get the flag which joins the first
triangle strip to the last one with a twist. JoinU must
also be set if this is set. Used when building some non-
orientable surfaces.
* obj.TwistUOff () - Set/Get the flag which joins the first
triangle strip to the last one with a twist. JoinU must
also be set if this is set. Used when building some non-
orientable surfaces.
* obj.SetTwistV (int ) - Set/Get the flag which joins the
ends of the triangle strips with a twist. JoinV must also
be set if this is set. Used when building some non-
orientable surfaces.
* int = obj.GetTwistV () - Set/Get the flag which joins the
ends of the triangle strips with a twist. JoinV must also
be set if this is set. Used when building some non-
orientable surfaces.
* obj.TwistVOn () - Set/Get the flag which joins the ends of
the triangle strips with a twist. JoinV must also be set
if this is set. Used when building some non-orientable
surfaces.
* obj.TwistVOff () - Set/Get the flag which joins the ends
of the triangle strips with a twist. JoinV must also be
set if this is set. Used when building some non-orientable
surfaces.
* obj.SetClockwiseOrdering (int ) - Set/Get the flag which
determines the ordering of the the vertices forming the
triangle strips. The ordering of the points being inserted
into the triangle strip is important because it determines
the direction of the normals for the lighting. If set, the
ordering is clockwise, otherwise the ordering is anti-
clockwise. Default is true (i.e. clockwise ordering).
* int = obj.GetClockwiseOrdering () - Set/Get the flag which
determines the ordering of the the vertices forming the
triangle strips. The ordering of the points being inserted
into the triangle strip is important because it determines
the direction of the normals for the lighting. If set, the
ordering is clockwise, otherwise the ordering is anti-
clockwise. Default is true (i.e. clockwise ordering).
* obj.ClockwiseOrderingOn () - Set/Get the flag which
determines the ordering of the the vertices forming the
triangle strips. The ordering of the points being inserted
into the triangle strip is important because it determines
the direction of the normals for the lighting. If set, the
ordering is clockwise, otherwise the ordering is anti-
clockwise. Default is true (i.e. clockwise ordering).
* obj.ClockwiseOrderingOff () - Set/Get the flag which
determines the ordering of the the vertices forming the
triangle strips. The ordering of the points being inserted
into the triangle strip is important because it determines
the direction of the normals for the lighting. If set, the
ordering is clockwise, otherwise the ordering is anti-
clockwise. Default is true (i.e. clockwise ordering).
* obj.SetDerivativesAvailable (int ) - Set/Get the flag
which determines whether derivatives are available from
the parametric function (i.e., whether the Evaluate()
method returns valid derivatives).
* int = obj.GetDerivativesAvailable () - Set/Get the flag
which determines whether derivatives are available from
the parametric function (i.e., whether the Evaluate()
method returns valid derivatives).
* obj.DerivativesAvailableOn () - Set/Get the flag which
determines whether derivatives are available from the
parametric function (i.e., whether the Evaluate() method
returns valid derivatives).
* obj.DerivativesAvailableOff () - Set/Get the flag which
determines whether derivatives are available from the
parametric function (i.e., whether the Evaluate() method
returns valid derivatives).
* FreeMat_Documentation
* Visualization_Toolkit_Common_Classes
* Generated on Thu Jul 25 2013 17:18:30 for FreeMat by
doxygen_ 1.8.1.1
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