[vtk-developers] question about vtkxml file format

[Simon Warfield]

The vtkXMLUnstructuredGrid reader reads data with cell information 
specified through a connectivity array, an offsets array and a cell type 
array.   
http://www.vtk.org/doc/nightly/html/classvtkXMLUnstructuredGridReader.html

It seems to me the offsets array must specify the index of one past the 
end of the corresponding cell, rather than the end of the corresponding 
cell as the documentation suggests.  Or perhaps indexes count from 1 
instead of from 0.
This test here uses data that has a cell offsets array constructed to 
point one past the end of the cell:
http://public.kitware.com/cgi-bin/viewcvs.cgi/*checkout*/IO/Testing/Tcl/TestXMLUnstructuredGridIO.tcl?root=VTK&content-type=text/plain

The example at the end of this documentation http://www.vtk.org/pdf/file-formats.pdf  also offsets by one past the end of the cell.  For example, it quadrilaterals running 0,1,2,3 the index of the 'end of the cell' is 4.  


Can that be right ?

-- 
Simon K. Warfield, Ph.D. warfield at bwh.harvard.edu Phone:617-732-7090
http://www.spl.harvard.edu/~warfield           FAX:  617-582-6033
Associate Professor of Radiology,          Harvard Medical School
Director, Computational Radiology Laboratory
Thorn 329, Dept Radiology,  Brigham and Women's Hospital 
75 Francis St, Boston, MA, 02115
MA 280, Dept Radiology, Children's Hospital Phone: 617-355-4566