vtk
Class vtkDelaunay2D

java.lang.Object
  vtk.vtkObjectBase
      vtk.vtkObject
          vtk.vtkProcessObject
              vtk.vtkSource
                  vtk.vtkPolyDataSource
                      vtk.vtkDelaunay2D

All Implemented Interfaces:

java.io.Serializable

public class vtkDelaunay2D

extends vtkPolyDataSource

implements java.io.Serializable

vtkDelaunay2D - create 2D Delaunay triangulation of input points. vtkDelaunay2D is a filter that constructs a 2D Delaunay triangulation from a list of input points. These points may be represented by any dataset of type vtkPointSet and subclasses. The output of the filter is a polygonal dataset. Usually the output is a triangle mesh, but if a non-zero alpha distance value is specified (called the "alpha" value), then only triangles, edges, and vertices lying within the alpha radius are output. In other words, non-zero alpha values may result in arbitrary combinations of triangles, lines, and vertices. (The notion of alpha value is derived from Edelsbrunner's work on "alpha shapes".) Also, it is possible to generate "constrained triangulations" using this filter. A constrained triangulation is one where edges and loops (i.e., polygons) can be defined and the triangulation will preserve them (read on for more information). The 2D Delaunay triangulation is defined as the triangulation that satisfies the Delaunay criterion for n-dimensional simplexes (in this case n=2 and the simplexes are triangles). This criterion states that a circumsphere of each simplex in a triangulation contains only the n+1 defining points of the simplex. (See "The Visualization Toolkit" text for more information.) In two dimensions, this translates into an optimal triangulation. That is, the maximum interior angle of any triangle is less than or equal to that of any possible triangulation. Delaunay triangulations are used to build topological structures from unorganized (or unstructured) points. The input to this filter is a list of points specified in 3D, even though the triangulation is 2D. Thus the triangulation is constructed in the x-y plane, and the z coordinate is ignored (although carried through to the output). If you desire to triangulate in a different plane, you can use the vtkTransformFilter to transform the points into and out of the x-y plane or you can specify a transform to the Delaunay2D directly. In the latter case, the input points are transformed, the transformed points are triangulated, and the output will use the triangulated topology for the original (non-transformed) points. This avoids transforming the data back as would be required when using the vtkTransformFilter method. Specifying a transform directly also allows any transform to be used: rigid, non-rigid, non-invertible, etc. If an input transform is used, then alpha values are applied (for the most part) in the original data space. The exception is when BoundingTriangulation is on. In this case, alpha values are applied in the original data space unless a cell uses a bounding vertex. The Delaunay triangulation can be numerically sensitive in some cases. To prevent problems, try to avoid injecting points that will result in triangles with bad aspect ratios (1000:1 or greater). In practice this means inserting points that are "widely dispersed", and enables smooth transition of triangle sizes throughout the mesh. (You may even want to add extra points to create a better point distribution.) If numerical problems are present, you will see a warning message to this effect at the end of the triangulation process. To create constrained meshes, you must define an additional input. This input is an instance of vtkPolyData which contains lines, polylines, and/or polygons that define constrained edges and loops. Only the topology of (lines and polygons) from this second input are used. The topology is assumed to reference points in the input point set (the one to be triangulated). In other words, the lines and polygons use point ids from the first input point set. Lines and polylines found in the input will be mesh edges in the output. Polygons define a loop with inside and outside regions. The inside of the polygon is determined by using the right-hand-rule, i.e., looking down the z-axis a polygon should be ordered counter-clockwise. Holes in a polygon should be ordered clockwise. If you choose to create a constrained triangulation, the final mesh may not satisfy the Delaunay criterion. (Noted: the lines/polygon edges must not intersect when projected onto the 2D plane. It may not be possible to recover all edges due to not enough points in the triangulation, or poorly defined edges (coincident or excessively long). The form of the lines or polygons is a list of point ids that correspond to the input point ids used to generate the triangulation.) If an input transform is used, constraints are defined in the "transformed" space. So when the right hand rule is used for a polygon constraint, that operation is applied using the transformed points. Since the input transform can be any transformation (rigid or non-rigid), care must be taken in constructing constraints when an input transform is used. JavaBean wrapper for vtkDelaunay2D object.

Author:

vtk2jbean Automatic JavaBean wrapper for VTK.

See Also:

vtkDelaunay3D, vtkTransformFilter, Serialized Form

Field Summary

protected java.beans.PropertyChangeSupport

changes

Fields inherited from class vtk.vtkObjectBase

vtkId

Constructor Summary

	vtkDelaunay2D()
protected	vtkDelaunay2D(int dmy)

Method Summary

void	boundingTriangulationOff() Boolean controls whether bounding triangulation points (and associated triangles) are included in the output.
void	boundingTriangulationOn() Boolean controls whether bounding triangulation points (and associated triangles) are included in the output.
double	getAlpha() Specify alpha (or distance) value to control output of this filter.
double	getAlphaMaxValue() Specify alpha (or distance) value to control output of this filter.
double	getAlphaMinValue() Specify alpha (or distance) value to control output of this filter.
int	getBoundingTriangulation() Boolean controls whether bounding triangulation points (and associated triangles) are included in the output.
java.lang.String	getClassName() Return the class name as a string.
vtkPointSet	getInput() Set / get the input data or filter.
double	getOffset() Specify a multiplier to control the size of the initial, bounding Delaunay triangulation.
double	getOffsetMaxValue() Specify a multiplier to control the size of the initial, bounding Delaunay triangulation.
double	getOffsetMinValue() Specify a multiplier to control the size of the initial, bounding Delaunay triangulation.
vtkPolyData	getSource() Specify the source object used to specify constrained edges and loops.
vtkDelaunay2D	getThisDelaunay2D()
double	getTolerance() Specify a tolerance to control discarding of closely spaced points.
double	getToleranceMaxValue() Specify a tolerance to control discarding of closely spaced points.
double	getToleranceMinValue() Specify a tolerance to control discarding of closely spaced points.
vtkAbstractTransform	getTransform() Set / get the transform which is applied to points to generate a 2D problem.
int	isA(java.lang.String id0) Return 1 if this class is the same type of (or a subclass of) the named class.
void	setAlpha(double id0) Specify alpha (or distance) value to control output of this filter.
void	setBoundingTriangulation(int id0) Boolean controls whether bounding triangulation points (and associated triangles) are included in the output.
void	setInput(vtkPointSet id0) Set / get the input data or filter.
void	setOffset(double id0) Specify a multiplier to control the size of the initial, bounding Delaunay triangulation.
void	setSource(vtkPolyData id0) Specify the source object used to specify constrained edges and loops.
void	setTolerance(double id0) Specify a tolerance to control discarding of closely spaced points.
void	setTransform(vtkAbstractTransform id0) Set / get the transform which is applied to points to generate a 2D problem.
protected void	VTKCastInit()
void	VTKInit()

Methods inherited from class vtk.vtkPolyDataSource

getOutput, getOutput, getThisPolyDataSource, setOutput

Methods inherited from class vtk.vtkSource

computeInputUpdateExtents, getNumberOfOutputs, getOutputIndex, getReleaseDataFlag, getThisSource, inRegisterLoop, propagateUpdateExtent, releaseDataFlagOff, releaseDataFlagOn, setReleaseDataFlag, triggerAsynchronousUpdate, unRegister, unRegisterAllOutputs, update, updateData, updateInformation, updateWholeExtent

Methods inherited from class vtk.vtkProcessObject

abortExecuteOff, abortExecuteOn, getAbortExecute, getErrorCode, getNumberOfInputs, getProgress, getProgressMaxValue, getProgressMinValue, getProgressText, getThisProcessObject, removeAllInputs, setAbortExecute, setProgress, setProgressText, squeezeInputArray, updateProgress

Methods inherited from class vtk.vtkObject

AddObserver, breakOnError, debugOff, debugOn, getDebug, getGlobalWarningDisplay, getMTime, getThisObject, globalWarningDisplayOff, globalWarningDisplayOn, hasObserver, hasObserver, invokeEvent, invokeEvent, modified, Print, PrintRevisions, register, removeObserver, removeObservers, removeObservers, setDebug, setGlobalWarningDisplay

Methods inherited from class vtk.vtkObjectBase

addPropertyChangeListener, finalize, getReferenceCount, getThisObjectBase, isTypeOf, removePropertyChangeListener, setReferenceCount, VTKDelete

Methods inherited from class java.lang.Object

clone, equals, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

changes

protected java.beans.PropertyChangeSupport changes

Constructor Detail

vtkDelaunay2D

public vtkDelaunay2D()

vtkDelaunay2D

protected vtkDelaunay2D(int dmy)

Method Detail

getThisDelaunay2D

public vtkDelaunay2D getThisDelaunay2D()

getClassName

public java.lang.String getClassName()

Description copied from class: vtkObjectBase

Return the class name as a string. This method is defined in all subclasses of vtkObjectBase with the vtkTypeRevisionMacro found in vtkSetGet.h.

Overrides:

getClassName in class vtkPolyDataSource

isA

public int isA(java.lang.String id0)

Description copied from class: vtkObjectBase

Return 1 if this class is the same type of (or a subclass of) the named class. Returns 0 otherwise. This method works in combination with vtkTypeRevisionMacro found in vtkSetGet.h.

Overrides:

isA in class vtkPolyDataSource

setSource

public void setSource(vtkPolyData id0)

Specify the source object used to specify constrained edges and loops. (This is optional.) If set, and lines/polygons are defined, a constrained triangulation is created. The lines/polygons are assumed to reference points in the input point set (i.e. point ids are identical in the input and source).

getSource

public vtkPolyData getSource()

Specify the source object used to specify constrained edges and loops. (This is optional.) If set, and lines/polygons are defined, a constrained triangulation is created. The lines/polygons are assumed to reference points in the input point set (i.e. point ids are identical in the input and source).

setAlpha

public void setAlpha(double id0)

Specify alpha (or distance) value to control output of this filter. For a non-zero alpha value, only edges or triangles contained within a sphere centered at mesh vertices will be output. Otherwise, only triangles will be output.

getAlphaMinValue

public double getAlphaMinValue()

Specify alpha (or distance) value to control output of this filter. For a non-zero alpha value, only edges or triangles contained within a sphere centered at mesh vertices will be output. Otherwise, only triangles will be output.

getAlphaMaxValue

public double getAlphaMaxValue()

Specify alpha (or distance) value to control output of this filter. For a non-zero alpha value, only edges or triangles contained within a sphere centered at mesh vertices will be output. Otherwise, only triangles will be output.

getAlpha

public double getAlpha()

Specify alpha (or distance) value to control output of this filter. For a non-zero alpha value, only edges or triangles contained within a sphere centered at mesh vertices will be output. Otherwise, only triangles will be output.

setTolerance

public void setTolerance(double id0)

Specify a tolerance to control discarding of closely spaced points. This tolerance is specified as a fraction of the diagonal length of the bounding box of the points.

getToleranceMinValue

public double getToleranceMinValue()

Specify a tolerance to control discarding of closely spaced points. This tolerance is specified as a fraction of the diagonal length of the bounding box of the points.

getToleranceMaxValue

public double getToleranceMaxValue()

Specify a tolerance to control discarding of closely spaced points. This tolerance is specified as a fraction of the diagonal length of the bounding box of the points.

getTolerance

public double getTolerance()

Specify a tolerance to control discarding of closely spaced points. This tolerance is specified as a fraction of the diagonal length of the bounding box of the points.

setOffset

public void setOffset(double id0)

Specify a multiplier to control the size of the initial, bounding Delaunay triangulation.

getOffsetMinValue

public double getOffsetMinValue()

Specify a multiplier to control the size of the initial, bounding Delaunay triangulation.

getOffsetMaxValue

public double getOffsetMaxValue()

Specify a multiplier to control the size of the initial, bounding Delaunay triangulation.

getOffset

public double getOffset()

Specify a multiplier to control the size of the initial, bounding Delaunay triangulation.

setBoundingTriangulation

public void setBoundingTriangulation(int id0)

Boolean controls whether bounding triangulation points (and associated triangles) are included in the output. (These are introduced as an initial triangulation to begin the triangulation process. This feature is nice for debugging output.)

getBoundingTriangulation

public int getBoundingTriangulation()

Boolean controls whether bounding triangulation points (and associated triangles) are included in the output. (These are introduced as an initial triangulation to begin the triangulation process. This feature is nice for debugging output.)

boundingTriangulationOn

public void boundingTriangulationOn()

Boolean controls whether bounding triangulation points (and associated triangles) are included in the output. (These are introduced as an initial triangulation to begin the triangulation process. This feature is nice for debugging output.)

boundingTriangulationOff

public void boundingTriangulationOff()

Boolean controls whether bounding triangulation points (and associated triangles) are included in the output. (These are introduced as an initial triangulation to begin the triangulation process. This feature is nice for debugging output.)

setInput

public void setInput(vtkPointSet id0)

Set / get the input data or filter.

getInput

public vtkPointSet getInput()

Set / get the input data or filter.

setTransform

public void setTransform(vtkAbstractTransform id0)

Set / get the transform which is applied to points to generate a 2D problem. This maps a 3D dataset into a 2D dataset where triangulation can be done on the XY plane. The points are transformed and triangulated. The topology of triangulated points is used as the output topology. The output points are the original (untransformed) points. The transform can be any subclass of vtkAbstractTransform (thus it does not need to be a linear or invertible transform).

getTransform

public vtkAbstractTransform getTransform()

Set / get the transform which is applied to points to generate a 2D problem. This maps a 3D dataset into a 2D dataset where triangulation can be done on the XY plane. The points are transformed and triangulated. The topology of triangulated points is used as the output topology. The output points are the original (untransformed) points. The transform can be any subclass of vtkAbstractTransform (thus it does not need to be a linear or invertible transform).

VTKInit

public void VTKInit()

Overrides:

VTKInit in class vtkObject

VTKCastInit

protected void VTKCastInit()

Overrides:

VTKCastInit in class vtkPolyDataSource