[vtkusers] Getting entire Volume into a buffer :: Help need!!!

[cspl]

Hi all,
   I am using vtkVolumeRaycastMIPFuntion to apply Maximum intensity
projection on the volume. I could able to use it properly in my application.
Now my problem is to store the output volume into a buffer. I want the whole
output i.e. if we give 5 images as input then i should get a volume of 5
images of output into a buffer for further processing. I could get only one
slice using GetPixelData of vtkRenderWindow class. I want the output volume
after performing the rendering on the input volume. I checked vtkRenderer,
vtkRenderWindow, vtkVolume class for any related function but could not
find. Is there any other class which would help me out in returning the
entire output volume into a buffer rather than a slice. Please help me out
in this regard.

  Thanks in advance.

-Regards,
  Sateesh.