[vtkusers] Issue with displaying headsq/quarter data

[Ryan MacConnell]

I am rendering the headsq/quarter data and it seems that the left and
right sides of the data are reversed based on the original description
of the data from "Marching Cubes: A High Resolution 3D Surface
Contruction Algorithm", Lorensen and Cline which states the the bullet
wound was on the left side of the face.

I consulted The Visualization Toolkit 3rd Edition book and found what
seems to be a contradiction.  If you reference Figure 6-11b which is
generated by headBone.tcl the tube is on the left side of the mouth
while Figure 12-3 from Medical2.cxx  shows the tube on the right side
of mouth.  Both seem to be using the same dataset and are both using
vtkVolume16Readers.  I also used VolView to view the dataset and it
has the tube/bullet wound on the right side. Can someone please let me
know what is causing this difference?  Are there two different
datasets being used because I could not find any difference between
the two pieces of code which would indicate the cause of left and
right sides being switched.

Thank you,
Ryan MacConnell