The perspective shear-warp algorithm in a virtual environment

Since the original paper of Lacroute and Levoy (1994), where the shear-warp factorization was also shown for perspective projections, a lot of work has been carried out using the shear-warp factorization with parallel projections. However, none of it has proved or improved the algorithm for the perspective projection. Also in Lacroute´s Volpack library, the perspective shear-warp volume rendering algorithm is missing. This paper reports on an implementation of the perspective shear-warp algorithm, which includes enhancements for its application in immersive virtual environments. Furthermore, a mathematical proof for the correctness of the permutation of projection and warp is provided, so far a basic assumption of the shear-warp perspective projection.