Fast volume rendering using adaptive block subdivision

We propose a fast volume rendering scheme that greatly reduces ray-casting overheads by adaptive block subdivision. We first apply a uniform space subdivision for constructing the adaptively subdivided volume. Then we merge coherent uniform blocks to generate adaptive-sized blocks that are efficient for leaping space. To accomplish this, an efficient block merging algorithm based on a boundary following and scan-filling strategy is proposed. Experimental results show that our fast volume rendering scheme is superior to other schemes in constructing a data structure for fast rendering; due to its simple construction approach, construction speed is more than three times faster than a hierarchical data structure, the octree. A 25% to 70% performance gain in rendering time over the octree is also exhibited. The additional advantages of our scheme are a stable acceleration for animation and an associativity with a compression-based volume rendering.