Tangent through a given point on a surface

Hi all, 

 

how can I calculate a tangent (in 3d usually a plane) through a given point
on a surface using VTK? I already tried the following:

-          Use an implicit dataset to transform polydata to an implicit
surface representation and then

-          calculate the gradient at the given point using the method
FunctionGradient(.). 

However, the gradient I received seems to be wrong (which is (0, 0, 1)). 

 

Any help would be appreciated.

_______________________________________________
Powered by www.kitware.com

Visit other Kitware open-source projects at http://www.kitware.com/opensource/opensource.html

Please keep messages on-topic and check the VTK FAQ at: http://www.vtk.org/Wiki/VTK_FAQ

Search the list archives at: http://markmail.org/search/?q=vtkusers

Follow this link to subscribe/unsubscribe:
https://vtk.org/mailman/listinfo/vtkusers