[vtkusers] get shaded volume data from vtkVolumeTextureMapper3D

[David Barnes]

Hi,

is it possible to obtain the *shaded* data volume (3d array) that
vtkVolumeTextureMapper3D (or its derived class
vtkOpenGLVolumeTextureMapper3D)?   If this class is doing volume
rendering by drawing multiple textured planes back to front, then it
presumably is preparing a 3D RGBA texture from the user supplied
volume data (scalar float) and transfer functions.  I would love to
get access to the RGBA data that gets rendered on the card, so that a
set of slices can be saved for another use.

Is this possible, and is there a public interface to fetch what I want?

Thanks for any help.

 - david.