Section: Visualization Toolkit Graphics Classes
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. (If you wish to create 2D triangulations see vtkDelaunay2D.) The output is an unstructured grid. The Delaunay triangulation can be numerically sensitive. 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 an instance of class vtkDelaunay3D, simply invoke its constructor as follows
obj = vtkDelaunay3D
obj
is an instance of the vtkDelaunay3D class.
string = obj.GetClassName ()
int = obj.IsA (string name)
vtkDelaunay3D = obj.NewInstance ()
vtkDelaunay3D = obj.SafeDownCast (vtkObject o)
obj.SetAlpha (double )
- Specify alpha (or distance) value to control output of this filter.
For a non-zero alpha value, only edges, faces, or tetra contained
within the circumsphere (of radius alpha) will be output. Otherwise,
only tetrahedra will be output.
double = obj.GetAlphaMinValue ()
- Specify alpha (or distance) value to control output of this filter.
For a non-zero alpha value, only edges, faces, or tetra contained
within the circumsphere (of radius alpha) will be output. Otherwise,
only tetrahedra will be output.
double = obj.GetAlphaMaxValue ()
- Specify alpha (or distance) value to control output of this filter.
For a non-zero alpha value, only edges, faces, or tetra contained
within the circumsphere (of radius alpha) will be output. Otherwise,
only tetrahedra will be output.
double = obj.GetAlpha ()
- Specify alpha (or distance) value to control output of this filter.
For a non-zero alpha value, only edges, faces, or tetra contained
within the circumsphere (of radius alpha) will be output. Otherwise,
only tetrahedra will be output.
obj.SetTolerance (double )
- 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.
double = obj.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.
double = obj.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.
double = obj.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.
obj.SetOffset (double )
- Specify a multiplier to control the size of the initial, bounding
Delaunay triangulation.
double = obj.GetOffsetMinValue ()
- Specify a multiplier to control the size of the initial, bounding
Delaunay triangulation.
double = obj.GetOffsetMaxValue ()
- Specify a multiplier to control the size of the initial, bounding
Delaunay triangulation.
double = obj.GetOffset ()
- Specify a multiplier to control the size of the initial, bounding
Delaunay triangulation.
obj.SetBoundingTriangulation (int )
- 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.)
int = obj.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.)
obj.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.)
obj.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.)
obj.SetLocator (vtkIncrementalPointLocator locator)
- Set / get a spatial locator for merging points. By default,
an instance of vtkPointLocator is used.
vtkIncrementalPointLocator = obj.GetLocator ()
- Set / get a spatial locator for merging points. By default,
an instance of vtkPointLocator is used.
obj.CreateDefaultLocator ()
- Create default locator. Used to create one when none is specified. The
locator is used to eliminate "coincident" points.
obj.InsertPoint (vtkUnstructuredGrid Mesh, vtkPoints points, vtkIdType id, double x[3], vtkIdList holeTetras)
- This is a helper method used with InitPointInsertion() to create
tetrahedronalizations of points. Its purpose is to inject point at
coordinates specified into tetrahedronalization. The point id is an index
into the list of points in the mesh structure. (See
vtkDelaunay3D::InitPointInsertion() for more information.) When you have
completed inserting points, traverse the mesh structure to extract desired
tetrahedra (or tetra faces and edges).The holeTetras id list lists all the
tetrahedra that are deleted (invalid) in the mesh structure.
obj.EndPointInsertion ()
- Invoke this method after all points have been inserted. The purpose of
the method is to clean up internal data structures. Note that the
(vtkUnstructuredGrid *)Mesh returned from InitPointInsertion() is NOT
deleted, you still are responsible for cleaning that up.
long = obj.GetMTime ()
- Return the MTime also considering the locator.