[vtkusers] rendering to images

[Tim Newsham]

Hi,

   What is the recommended way to render a vtk pipeline into an
image format without displaying the data?  I noticed that there
is a vtkWindowToImageFilter class that can be used to read out
an image from a window.  I would like to build up a pipeline,
have it rendered to a hidden window somehow, and then extract
the data from this filter (or something similar to it) into an
internal (ie. not file) format suitable for passing to a gui
toolkit such as gtk.

Tim N.