Section: Visualization Toolkit Graphics Classes
Gauss Curvature
discrete Gauss curvature (K) computation,
Mean Curvature
NB: dihedral_angle is the ORIENTED angle between -PI and PI,
this means that the surface is assumed to be orientable
the computation creates the orientation
The units of Mean Curvature are [1/m]
Excepting spherical and planar surfaces which have equal principal curvatures,
the curvature at a point on a surface varies with the direction one "sets off"
from the point. For all directions, the curvature will pass through two extrema:
directions to each other.
NB. The sign of the Gauss curvature is a geometric ivariant, it should be +ve when the surface looks like a sphere, -ve when it looks like a saddle, however, the sign of the Mean curvature is not, it depends on the convention for normals - This code assumes that normals point outwards (ie from the surface of a sphere outwards). If a given mesh produces curvatures of opposite senses then the flag InvertMeanCurvature can be set and the Curvature reported by the Mean calculation will be inverted.
.SECTION Thanks Philip Batchelor philipp.batchelor@kcl.ac.uk for creating and contributing the class and Andrew Maclean a.maclean@acfr.usyd.edu.au for cleanups and fixes. Thanks also to Goodwin Lawlor for contributing patch to calculate principal curvatures
To create an instance of class vtkCurvatures, simply invoke its constructor as follows
obj = vtkCurvatures
obj
is an instance of the vtkCurvatures class.
string = obj.GetClassName ()
int = obj.IsA (string name)
vtkCurvatures = obj.NewInstance ()
vtkCurvatures = obj.SafeDownCast (vtkObject o)
obj.SetCurvatureType (int )
- Set/Get Curvature type
VTK_CURVATURE_GAUSS: Gaussian curvature, stored as
DataArray "Gauss_Curvature"
VTK_CURVATURE_MEAN : Mean curvature, stored as
DataArray "Mean_Curvature"
int = obj.GetCurvatureType ()
- Set/Get Curvature type
VTK_CURVATURE_GAUSS: Gaussian curvature, stored as
DataArray "Gauss_Curvature"
VTK_CURVATURE_MEAN : Mean curvature, stored as
DataArray "Mean_Curvature"
obj.SetCurvatureTypeToGaussian ()
- Set/Get Curvature type
VTK_CURVATURE_GAUSS: Gaussian curvature, stored as
DataArray "Gauss_Curvature"
VTK_CURVATURE_MEAN : Mean curvature, stored as
DataArray "Mean_Curvature"
obj.SetCurvatureTypeToMean ()
- Set/Get Curvature type
VTK_CURVATURE_GAUSS: Gaussian curvature, stored as
DataArray "Gauss_Curvature"
VTK_CURVATURE_MEAN : Mean curvature, stored as
DataArray "Mean_Curvature"
obj.SetCurvatureTypeToMaximum ()
- Set/Get Curvature type
VTK_CURVATURE_GAUSS: Gaussian curvature, stored as
DataArray "Gauss_Curvature"
VTK_CURVATURE_MEAN : Mean curvature, stored as
DataArray "Mean_Curvature"
obj.SetCurvatureTypeToMinimum ()
- Set/Get the flag which inverts the mean curvature calculation for
meshes with inward pointing normals (default false)
obj.SetInvertMeanCurvature (int )
- Set/Get the flag which inverts the mean curvature calculation for
meshes with inward pointing normals (default false)
int = obj.GetInvertMeanCurvature ()
- Set/Get the flag which inverts the mean curvature calculation for
meshes with inward pointing normals (default false)
obj.InvertMeanCurvatureOn ()
- Set/Get the flag which inverts the mean curvature calculation for
meshes with inward pointing normals (default false)
obj.InvertMeanCurvatureOff ()
- Set/Get the flag which inverts the mean curvature calculation for
meshes with inward pointing normals (default false)