VTK
|
reduce height field (represented as image) to reduced TIN More...
#include <vtkGreedyTerrainDecimation.h>
Inherits vtkPolyDataAlgorithm.
Public Types | |
typedef vtkPolyDataAlgorithm | Superclass |
Public Member Functions | |
virtual int | IsA (const char *type) |
vtkGreedyTerrainDecimation * | NewInstance () const |
void | PrintSelf (ostream &os, vtkIndent indent) |
virtual void | SetErrorMeasure (int) |
virtual int | GetErrorMeasure () |
void | SetErrorMeasureToNumberOfTriangles () |
void | SetErrorMeasureToSpecifiedReduction () |
void | SetErrorMeasureToAbsoluteError () |
void | SetErrorMeasureToRelativeError () |
virtual void | SetNumberOfTriangles (vtkIdType) |
virtual vtkIdType | GetNumberOfTriangles () |
virtual void | SetReduction (double) |
virtual double | GetReduction () |
virtual void | SetAbsoluteError (double) |
virtual double | GetAbsoluteError () |
virtual void | SetRelativeError (double) |
virtual double | GetRelativeError () |
virtual void | SetBoundaryVertexDeletion (int) |
virtual int | GetBoundaryVertexDeletion () |
virtual void | BoundaryVertexDeletionOn () |
virtual void | BoundaryVertexDeletionOff () |
virtual void | SetComputeNormals (int) |
virtual int | GetComputeNormals () |
virtual void | ComputeNormalsOn () |
virtual void | ComputeNormalsOff () |
Static Public Member Functions | |
static int | IsTypeOf (const char *type) |
static vtkGreedyTerrainDecimation * | SafeDownCast (vtkObjectBase *o) |
static vtkGreedyTerrainDecimation * | New () |
Protected Member Functions | |
virtual vtkObjectBase * | NewInstanceInternal () const |
vtkGreedyTerrainDecimation () | |
~vtkGreedyTerrainDecimation () | |
virtual int | RequestData (vtkInformation *, vtkInformationVector **, vtkInformationVector *) |
virtual int | FillInputPortInformation (int port, vtkInformation *info) |
void | ComputePointNormal (int i, int j, float n[3]) |
void | EstimateOutputSize (const vtkIdType numInputPts, vtkIdType &numPts, vtkIdType &numTris) |
virtual int | SatisfiesErrorMeasure (double error) |
void | InsertBoundaryVertices () |
vtkIdType | AddPointToTriangulation (vtkIdType inputPtId) |
vtkIdType | InsertNextPoint (vtkIdType inputPtId, double x[3]) |
double * | GetPoint (vtkIdType id) |
void | GetPoint (vtkIdType id, double x[3]) |
void | GetTerrainPoint (int i, int j, double x[3]) |
void | ComputeImageCoordinates (vtkIdType inputPtId, int ij[2]) |
int | InCircle (double x[3], double x1[3], double x2[3], double x3[3]) |
vtkIdType | FindTriangle (double x[3], vtkIdType ptIds[3], vtkIdType tri, double tol, vtkIdType nei[3], vtkIdList *neighbors, int &status) |
void | CheckEdge (vtkIdType ptId, double x[3], vtkIdType p1, vtkIdType p2, vtkIdType tri, int depth) |
void | UpdateTriangles (vtkIdType meshPtId) |
void | UpdateTriangle (vtkIdType triId, vtkIdType p1, vtkIdType p2, vtkIdType p3) |
void | UpdateTriangle (vtkIdType triId, int ij1[2], int ij2[2], int ij3[2], double h[4]) |
int | CharacterizeTriangle (int ij1[2], int ij2[2], int ij[3], int *&min, int *&max, int *&midL, int *&midR, int *&mid, int mid2[2], double h[3], double &hMin, double &hMax, double &hL, double &hR) |
Protected Attributes | |
int | ComputeNormals |
vtkFloatArray * | Normals |
int | ErrorMeasure |
vtkIdType | NumberOfTriangles |
double | Reduction |
double | AbsoluteError |
double | RelativeError |
int | BoundaryVertexDeletion |
vtkPolyData * | Mesh |
vtkPointData * | InputPD |
vtkPointData * | OutputPD |
vtkDoubleArray * | Points |
vtkDataArray * | Heights |
vtkIdType | CurrentPointId |
double | Tolerance |
vtkIdList * | Neighbors |
int | Dimensions [3] |
double | Origin [3] |
double | Spacing [3] |
vtkIdType | MaximumNumberOfTriangles |
double | Length |
vtkPriorityQueue * | TerrainError |
vtkGreedyTerrainDecimationTerrainInfoType * | TerrainInfo |
vtkGreedyTerrainDecimationPointInfoType * | PointInfo |
reduce height field (represented as image) to reduced TIN
vtkGreedyTerrainDecimation approximates a height field with a triangle mesh (triangulated irregular network - TIN) using a greedy insertion algorithm similar to that described by Garland and Heckbert in their paper "Fast Polygonal Approximations of Terrain and Height Fields" (Technical Report CMU-CS-95-181). The input to the filter is a height field (represented by a image whose scalar values are height) and the output of the filter is polygonal data consisting of triangles. The number of triangles in the output is reduced in number as compared to a naive tessellation of the input height field. This filter copies point data from the input to the output for those points present in the output.
An brief description of the algorithm is as follows. The algorithm uses a top-down decimation approach that initially represents the height field with two triangles (whose vertices are at the four corners of the image). These two triangles form a Delaunay triangulation. In an iterative fashion, the point in the image with the greatest error (as compared to the original height field) is injected into the triangulation. (Note that the single point with the greatest error per triangle is identified and placed into a priority queue. As the triangulation is modified, the errors from the deleted triangles are removed from the queue, error values from the new triangles are added.) The point whose error is at the top of the queue is added to the triangulaion modifying it using the standard incremental Delaunay point insertion (see vtkDelaunay2D) algorithm. Points are repeatedly inserted until the appropriate (user-specified) error criterion is met.
To use this filter, set the input and specify the error measure to be used. The error measure options are 1) the absolute number of triangles to be produced; 2) a fractional reduction of the mesh (numTris/maxTris) where maxTris is the largest possible number of triangles 2*(dims[0]-1)*(dims[1]-1); 3) an absolute measure on error (maximum difference in height field to reduced TIN); and 4) relative error (the absolute error is normalized by the diagonal of the bounding box of the height field).
Definition at line 91 of file vtkGreedyTerrainDecimation.h.
typedef vtkPolyDataAlgorithm vtkGreedyTerrainDecimation::Superclass |
Definition at line 94 of file vtkGreedyTerrainDecimation.h.
|
protected |
|
protected |
|
static |
|
virtual |
|
static |
|
protectedvirtual |
vtkGreedyTerrainDecimation* vtkGreedyTerrainDecimation::NewInstance | ( | ) | const |
void vtkGreedyTerrainDecimation::PrintSelf | ( | ostream & | os, |
vtkIndent | indent | ||
) |
|
static |
Instantiate the class.
|
virtual |
Specify how to terminate the algorithm: either as an absolute number of triangles, a relative number of triangles (normalized by the full resolution mesh), an absolute error (in the height field), or relative error (normalized by the length of the diagonal of the image).
|
virtual |
Specify how to terminate the algorithm: either as an absolute number of triangles, a relative number of triangles (normalized by the full resolution mesh), an absolute error (in the height field), or relative error (normalized by the length of the diagonal of the image).
|
inline |
Specify how to terminate the algorithm: either as an absolute number of triangles, a relative number of triangles (normalized by the full resolution mesh), an absolute error (in the height field), or relative error (normalized by the length of the diagonal of the image).
Definition at line 108 of file vtkGreedyTerrainDecimation.h.
|
inline |
Specify how to terminate the algorithm: either as an absolute number of triangles, a relative number of triangles (normalized by the full resolution mesh), an absolute error (in the height field), or relative error (normalized by the length of the diagonal of the image).
Definition at line 110 of file vtkGreedyTerrainDecimation.h.
|
inline |
Specify how to terminate the algorithm: either as an absolute number of triangles, a relative number of triangles (normalized by the full resolution mesh), an absolute error (in the height field), or relative error (normalized by the length of the diagonal of the image).
Definition at line 112 of file vtkGreedyTerrainDecimation.h.
|
inline |
Specify how to terminate the algorithm: either as an absolute number of triangles, a relative number of triangles (normalized by the full resolution mesh), an absolute error (in the height field), or relative error (normalized by the length of the diagonal of the image).
Definition at line 114 of file vtkGreedyTerrainDecimation.h.
|
virtual |
Specify the number of triangles to produce on output. (It is a good idea to make sure this is less than a tessellated mesh at full resolution.) You need to set this value only when the error measure is set to NumberOfTriangles.
|
virtual |
Specify the number of triangles to produce on output. (It is a good idea to make sure this is less than a tessellated mesh at full resolution.) You need to set this value only when the error measure is set to NumberOfTriangles.
|
virtual |
Specify the reduction of the mesh (represented as a fraction). Note that a value of 0.10 means a 10% reduction. You need to set this value only when the error measure is set to SpecifiedReduction.
|
virtual |
Specify the reduction of the mesh (represented as a fraction). Note that a value of 0.10 means a 10% reduction. You need to set this value only when the error measure is set to SpecifiedReduction.
|
virtual |
Specify the absolute error of the mesh; that is, the error in height between the decimated mesh and the original height field. You need to set this value only when the error measure is set to AbsoluteError.
|
virtual |
Specify the absolute error of the mesh; that is, the error in height between the decimated mesh and the original height field. You need to set this value only when the error measure is set to AbsoluteError.
|
virtual |
Specify the relative error of the mesh; that is, the error in height between the decimated mesh and the original height field normalized by the diagonal of the image. You need to set this value only when the error measure is set to RelativeError.
|
virtual |
Specify the relative error of the mesh; that is, the error in height between the decimated mesh and the original height field normalized by the diagonal of the image. You need to set this value only when the error measure is set to RelativeError.
|
virtual |
Turn on/off the deletion of vertices on the boundary of a mesh. This may limit the maximum reduction that may be achieved.
|
virtual |
Turn on/off the deletion of vertices on the boundary of a mesh. This may limit the maximum reduction that may be achieved.
|
virtual |
Turn on/off the deletion of vertices on the boundary of a mesh. This may limit the maximum reduction that may be achieved.
|
virtual |
Turn on/off the deletion of vertices on the boundary of a mesh. This may limit the maximum reduction that may be achieved.
|
virtual |
Compute normals based on the input image. Off by default.
|
virtual |
Compute normals based on the input image. Off by default.
|
virtual |
Compute normals based on the input image. Off by default.
|
virtual |
Compute normals based on the input image. Off by default.
|
protectedvirtual |
|
protectedvirtual |
|
protected |
|
protected |
|
protectedvirtual |
|
protected |
|
protected |
|
protected |
|
protected |
|
protected |
|
protected |
|
protected |
|
protected |
|
protected |
|
protected |
|
protected |
|
protected |
|
protected |
|
protected |
|
protected |
Definition at line 175 of file vtkGreedyTerrainDecimation.h.
|
protected |
Definition at line 176 of file vtkGreedyTerrainDecimation.h.
|
protected |
Definition at line 180 of file vtkGreedyTerrainDecimation.h.
|
protected |
Definition at line 181 of file vtkGreedyTerrainDecimation.h.
|
protected |
Definition at line 182 of file vtkGreedyTerrainDecimation.h.
|
protected |
Definition at line 183 of file vtkGreedyTerrainDecimation.h.
|
protected |
Definition at line 184 of file vtkGreedyTerrainDecimation.h.
|
protected |
Definition at line 185 of file vtkGreedyTerrainDecimation.h.
|
protected |
Definition at line 188 of file vtkGreedyTerrainDecimation.h.
|
protected |
Definition at line 189 of file vtkGreedyTerrainDecimation.h.
|
protected |
Definition at line 190 of file vtkGreedyTerrainDecimation.h.
|
protected |
Definition at line 191 of file vtkGreedyTerrainDecimation.h.
|
protected |
Definition at line 192 of file vtkGreedyTerrainDecimation.h.
|
protected |
Definition at line 193 of file vtkGreedyTerrainDecimation.h.
|
protected |
Definition at line 194 of file vtkGreedyTerrainDecimation.h.
|
protected |
Definition at line 195 of file vtkGreedyTerrainDecimation.h.
|
protected |
Definition at line 196 of file vtkGreedyTerrainDecimation.h.
|
protected |
Definition at line 197 of file vtkGreedyTerrainDecimation.h.
|
protected |
Definition at line 198 of file vtkGreedyTerrainDecimation.h.
|
protected |
Definition at line 199 of file vtkGreedyTerrainDecimation.h.
|
protected |
Definition at line 200 of file vtkGreedyTerrainDecimation.h.
|
protected |
Definition at line 203 of file vtkGreedyTerrainDecimation.h.
|
protected |
Definition at line 204 of file vtkGreedyTerrainDecimation.h.
|
protected |
Definition at line 205 of file vtkGreedyTerrainDecimation.h.