[vtkusers] problem computing the volume of a tetrahedral cell

[Vines, John (Civ, ARL/CISD)]

All,
I am trying to compute the volume of a tetrahedral cell using the "vtkTetra::ComputVolume()" method.  I do not understand why I am getting negative values?
 
At present I am converting hexahedral cells to tets using the vtkDataSetTriangleFilter().  I then feed in the points from each tetrahedral cell to the vtkTetra::ComputeVolume() method.
 
Any help is greatly appreciated, thanks for your time
 
John Vines
Army Research Laboratory
Scientific Visualization Team