[vtkusers] How do you turn on/off a pipeline?

[Prabhu Ramachandran]

hi,

A simple question:
	How does one turn on or off a particular VTK pipeline?  Or how 
does one disconnect a pipeline??

It would be useful in some circumstances to turn off a particular
pipeline, do some stuff, and then turn the pipeline segment back on.

One possible way is to connect the particular mapper/filter to another
dummy object that doesnt change and then reconnect it back.  But this
method isn't elegant.  I know that the MTime is used to determine if a
pipeline has been modified etc.  but there are no public methods to
set the MTime.  I looked around in the docs/book and couldnt really
find an answer.  Any help would be appreciated.

thanks,
prabhu