Department of Computer Science and Technology, Faculty of Creative Arts, Technologies and Science, University of Bedfordshire, D108 Park Square, Luton, Bedfordshire LU1 3JU, United Kingdom.
IEEE Trans Vis Comput Graph. 2013 Oct;19(10):1732-45. doi: 10.1109/TVCG.2012.151.
We present a novel approach for GPU-based high-quality volume rendering of large out-of-core volume data. By focusing on the locations and costs of ray traversal, we are able to significantly reduce the rendering time over traditional algorithms. We store a volume in an octree (of bricks); in addition, every brick is further split into regular macrocells. Our solutions move the branch-intensive accelerating structure traversal out of the GPU raycasting loop and introduce an efficient empty-space culling method by rasterizing the proxy geometry of a view-dependent cut of the octree nodes. This rasterization pass can capture all of the bricks that the ray penetrates in a per-pixel list. Since the per-pixel list is captured in a front-to-back order, our raycasting pass needs only to cast rays inside the tighter ray segments. As a result, we achieve two levels of empty space skipping: the brick level and the macrocell level. During evaluation and testing, this technique achieved 2 to 4 times faster rendering speed than a current state-of-the-art algorithm across a variety of data sets.
我们提出了一种新的基于 GPU 的大型核外体绘制方法。通过关注光线遍历的位置和成本，我们能够显著减少传统算法的渲染时间。我们将体数据存储在八叉树（brick）中；此外，每个 brick 进一步细分为常规的宏单元。我们的解决方案将分支密集的加速结构遍历移出 GPU 光线投射循环，并通过光栅化视相关的八叉树节点切割的代理几何体来引入高效的空区域剔除方法。这个光栅化过程可以在逐像素列表中捕获光线穿透的所有 brick。由于逐像素列表是从前到后捕获的，我们的光线投射过程只需要在更紧的光线段内投射光线。因此，我们实现了两个级别的空区域跳过：brick 级别和宏单元级别。在评估和测试过程中，该技术在各种数据集上的渲染速度比当前最先进的算法快 2 到 4 倍。
