VCG - Ridge Surface
Description
The RidgeSurface filter extracts ridge or valley surfaces from point (node) scalar data. This filter operates on unstructured grid data and produces geometry output.
Details
Extracts ridge surfaces
Input
vtkUnstructuredGrid
Output
None
Parameters
Name |
Description |
Values/Default |
| SmoothingRange |
Smoothing range for gradient computation.
|
1 |
|
| Mode |
Mode for orienting the eigenvectors. Either the eigenvectors at all nodes of the cell are oriented simultaneously, or pairwise, using the eigenvectors at the nodes that share an edge.
|
-
cell nodes PCA
-
edge nodes PCA
|
|
| Extremum |
Chose Ridges for the extraction of ridge surfaces and Valleys for the extraction of valley surfaces.
|
|
|
| UseBisection |
Use bisection for detecting cell edge intersection (interpolating both, gradient and Hessian) instead of linear interpolation of directional derivatives.
|
0 |
|
| ExcludeFLT_MAX |
Exclude nodes marked with FLT_MAX from extraction.
|
1 |
|
| ExcludeLonelyNodes |
Exclude nodes which do not have enough neighbors (due to FLT_MAX exclusion) from extraction.
|
1 |
|
| HessExtrEigenvalMin |
Minimum absolute value of second derivative across ridge (used for suppressing flat ridges).
|
0.0 |
|
| PCAsubdomMaxPerc |
The second largest absolute eigenvalue must not be larger than this percentage of the largest absolute eigenvalue.
|
1.0 |
|
| ScalarMin |
Minimum value of the scalar field for ridge extraction.
|
-1e20 |
|
| ScalarMax |
Maximum value of the scalar field for ridge extraction.
|
1e20 |
|
| ClipScalarMin |
Minimum value of the scalar clipping field for clipped ridge extraction.
|
-1e+20 |
|
| ClipScalarMax |
Maximum value of the scalar clipping field for clipped ridge extraction.
|
1e20 |
|
| MinSize |
Ridges with less than this number of triangles are suppressed.
|
1 |
|
| FilterByCell |
Ridge filtering is based on cells. Otherwise it is based on cell edges (recommended).
|
0 |
|
| CombineExceptions |
Instead of rejecting a triangle if a condition is violated at any corner, the violations are summed up and the the triangle is rejected if the count reaches or exceeds maxExceptions.
|
0 |
|
| MaxExceptions |
A triangle is rejected if it exhibits this count of exceptions.
|
1 |
|
| GenerateNormals |
Generate normals. However it is recommended to use the standard normals generation module instead.
|
0 |
|
Installation Instructions
Authors
Filip Sadlo
Acknowledgements
