[Paraview] Re: vtkPolyData

[Kent Eschenberg]

It seems you want your data to be stored as an unstructured grid with cells of 
type 1 (VTK_VERTEX). At each cell you will have one attribute which is a vector 
with 3 components.

Such a grid can be run through the Glyph module to put a line or arrow at each 
cell. Let Glyph do that - don't store the data as lines.

I haven't tried it but vtkStreamTracer should be able to generate streamlines 
from such a grid.

To obtain such a grid you will need to store your data in one of the file 
formats that can represent that type of grid. For example, both the VTK legacy 
and the VTK XML file formats can do this. Their ASCII versions are easy to 
generate.

Kent
Pittsburgh Supercomputing Center

Alessandro Bellina wrote:
 > Robert,
 > Since last time I posted this I was able to display something close to what
 > I want to do, but not quite exactly.
 >
 > I have a 2-D vector field that changes in time. In each time step the vector
 > has six coordinates V = {(x1,y1,z1), (x2,y2,z2)}. What I was ble to do
 > yesterday was plot them as <Lines>. So I did 2 points per line and that
 > worked OK. What I am interested in doing with this field is to plot a stream
 > (stream tracer.) So at some timestep in the future I want to be able to see
 > some of the old features of the previous timeteps. I think the stream tracer
 > filter does this but I can't use it with lines. Any other filters that do
 > this?
 >
 > The file then has <Points> <Lines>. And <Lines> have a connectivity and
 > offset table.
 >
 > I've seen some great renderings of stream-like behavior in ParaView.
 >
 > Ultimately I'd like to be able to color the stream to imply angle of
 > inclination  of the vectors with respect to a normal, I think this is
 > secondary.
 >
 > Thanks for your help,
 >
 > Alessandro