Volume rendering using seed-filling acceleration: supporting cut planes by fast reseeding.

OBJECTIVE Seed filling in view lattice is a method for accelerating volume rendering. Our previously published results on using seed filling had the limitation that they did not support cut planes. Cut planes are one of the main advantages of using volume rendering over surface rendering. In this article we describe the seed-filling acceleration technique and propose two fast reseeding processes that may be performed for each frame. MATERIALS AND METHODS The reseeding process performs a connected component search on the cut plane within the volume data set. The amount of processing done by a connected component search algorithm is proportional to N(2), assuming the data set size is N(3). We implemented two connected component search algorithms: one for orthogonal cut planes and another for oblique cut planes. We measured the time taken by the cutting and estimated the effect on the rendering performance when the cut plane was moved interactively. RESULTS Our measurements show that rendering rates of several frames per second can be achieved with a 266-MHz Pentium II PC, even when the object is interactively modified with cut planes during the rendering. CONCLUSIONS We have shown that the seed-filling algorithm is also applicable in situations where the displayed data is modified interactively using cut planes or objects. Applications in this regard include, for example, computer-aided surgery systems, where the instrument may be used to interactively perform the simulated cut in the data set.