Ray-casting is a widely used basic volume rendering algorithm. It can get high quality image but suffers from high computational complexity. A single-pass ray-casting algorithm is developed based on GPU(graphics processing unit)

and on the basis of this algorithm an accelerated algorithm is proposed based on space leaping technique. Noncontributing region in the volume data coded with octree data structure can be eliminated by space leaping. Then the burden of GPU may be reduced effectively. Only one fragment program is needed to generate ray direction

cast ray

skip empty voxels and terminate ray

et al. The experimental results illustrate the algorithm can significantly accelerate the reconstruction of the volume data containing a lot of empty voxels.