Documentation for vtkImplicitFunction

vtkImplicitFunction - abstract interface for implicit functions

Description:

vtkImplicitFunction specifies an abstract interface for implicit functions. Implicit functions are of the form F(x,y,z) = 0. Two primitive operations are required: the ability to evaluate the function, and the function gradient at a given point. Implicit functions are very powerful. It is possible to represent almost any type of geometry with implicit functions, especially if you use boolean combinations implicit functions (see vtkImplicitBoolean). vtkImplicitFunction provides a mechanism to transform the implicit function(s) via a transformation matrix. This capability can be used to translate, orient, or scale implicit functions. For example, a sphere implicit function can be transformed into an oriented ellipse. This is accomplished by using an instance of vtkTransform.

Caveats:

The transformation matrix transforms a point into the space of the implicit function (i.e., the model space). Typically we want to transform the implicit model into world coordinates. In this case the inverse of the transformation matrix is required.

See Also:

vtkTransform vtkSphere vtkCylinder vtkImplicitBoolean vtkPlane vtkPlanes vtkQuadric vtkImplicitVolume vtkSampleFunction vtkCutter vtkClipPolyData

Methods:

	void vtkImplicitFunction ()
	void vtkImplicitFunction ()
	const char *GetClassName ()
	void PrintSelf (unknown & ,vtkIndent )
	unsigned long GetMTime ()
	float FunctionValue (float )
	void FunctionGradient (float ,float )
	float EvaluateFunction (float )
	float EvaluateFunction (float ,float ,float )
	void EvaluateGradient (float ,float )
	void SetTransform (vtkTransform *)
	vtkTransform *GetTransform ()

Detailed Method Descriptions:

Overload standard modified time function. If Transform is modified, then this object is modified as well.

unsigned long GetMTime ()

Evaluate function at position x-y-z and return value. Point x[3] is transformed through transform (if provided).

float FunctionValue (float )

Evaluate function gradient at position x-y-z and pass back vector. Point x[3] is transformed through transform (if provided).

void FunctionGradient (float ,float )

Evaluate function at position x-y-z and return value. Must be implemented by derived class.

	float EvaluateFunction (float )
	float EvaluateFunction (float ,float ,float )

Evaluate function gradient at position x-y-z and pass back vector. Must be implemented by derived class.

void EvaluateGradient (float ,float )

Set/Get transformation matrix to transform implicit function.

	void SetTransform (vtkTransform *)
	vtkTransform *GetTransform ()