[vtkusers] confusion about scalars/vectors and field data

[Dominik Szczerba]

Hello,

What is the difference between SCALARS/VECTORS and field data. I have a 
dataset where I have many attributes - both scalars and vectors. Now if 
I read the PDF about legacy formats it is not clear to me e.g. if only 
one SCALARS or VECTORS entry is allowed per file and I can use many 
occurencies of them - or - I should use FIELD data instead. I have 
legacy files with multiple SCALARS and VECTORS entries - and these, 
while loading fine into paraview - crash my C++ codes on the following line:

int is = grid->GetPointData()->SetActiveScalars(argv[3]);
//is != -1 only on the first SCALARS, fails otherwise

Now if I re-save the file from paraview he will use only one SCALARS and 
VECTOR entries and pack everything else into FIELD fields. But it is not 
clearly pointed in the VTK file format definition. But if only one entry 
is allowed, why is paraview accepting it and VTK (CVS) not? What is 
happening here?

regards,
Dominik

-- 
Dominik Szczerba, Dr.
Computer Vision Lab CH-8092 Zurich
http://www.vision.ee.ethz.ch/~domi