[vtkusers] How to compute area of counter made by vtkContourWidget?

[normanius]

Hi Yihui Cao

The "3" in the warning message refers to VTK_LINE. From this I infer that
the contour is represented with lines only (a polyline). You have to first
"transform" the line into a polyline, or 

In case your contour is guaranteed to be convex, you can triangulate the
contour surface with vtkDelaunay2D. So, before calling the
vtkTriangleFilter, calculate the Delaunay triangulation on your contour
edges (Python code):


If the contour is not convex, things are a bit more complicated. You can try
to transform the polyline into a polygon. Unfortunately, I haven't found a
simple trick myself. Here some ideas that might help:
http://www.itk.org/Wiki/VTK/Examples/Cxx/GeometricObjects/Polygon
<http://www.itk.org/Wiki/VTK/Examples/Cxx/GeometricObjects/Polygon>  
http://vtk.1045678.n5.nabble.com/Polygon-triangulation-using-vtkPolugon-Triangulate-td1238179.html
<http://vtk.1045678.n5.nabble.com/Polygon-triangulation-using-vtkPolugon-Triangulate-td1238179.html>  






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