[vtkusers] animations/interactors & setting scalars in a geometric area

[Victor B. Putz]

Hullo, mighty VTK users!

A few questions for you:

(er, VTK 4.2 (I think), Python, Windows

1) I know this has been discussed briefly before, but I have written some
code which creates a model and then uses a VtkRenderWindowInteractor (I'm
using the Python VTK mapping) to display the model.  Good so far, and it
does that without complaining.  I would like to update the scalar values
associated with points in real-time, to display an animation of values
changing.

Earlier discussions I've found by searching imply that I need to use some
external time event mechanism to do this.  But I'm a little at sea there. 
Can anyone point me to an example--preferably using Python, simply because
I don't know how to do external timer events in Python, so I'm not sure
how much use a C++ example would be--but it would be better than nothing!)

2) I want to change the scalar values associated with points in a
VtkStructuredGrid.  I know how to set them when I'm creating the mesh, but
I'm less clear on how to select points based on geometry once the grid is
created... in other words something like "set the scalar value of all
points in parallel solid (xrange,yrange,zrange) to 42".

3) Since probably much of my questions can be answered by, ah, RTFM, I'd
like to know which FM to R--in other words, if I can't convince my
employer to purchase both "The Visualization Toolkit" and "The VTK User's
Guide"--any recommendation for one or the other, even on a usage-by-usage
basis?

Thanks--new to VTK and it's a fantastic kit, but it's a bit much to try
and assimilate just from the online class references.


-->VPutz