@article{pfister1995gradient,
  title={Gradient estimation and sheared interpolation for the cube architecture},
  author={Pfister, Hanspeter and Wessels, Frank and Kaufman, Arie},
  journal={Computers & Graphics},
  volume={19},
  number={5},
  pages={667--677},
  year={1995},
  publisher={Elsevier},
  abstract={We describe novel ways of gradient estimation and tri-linear interpolation for a real-time volume rendering system, using coherency between rays. We show simulation results that compare the proposed methods to traditional algorithms and present them in the context of Cube-3, a special-purpose architecture capable of rendering 5123 16-bit per voxel datasets at over 20 frames per second.}
}