This paper describes an algorithm to extract adaptive and quality quadrilateral/hexahedral meshes directly from volumetric data. First, a bottom-up surface topology preserving octree-based algorithm is applied to select a starting octree level. Then the dual contouring method is used to extract a preliminary uniform quad/hex mesh, which is decomposed into finer quads/hexes adaptively without introducing any hanging nodes. The positions of all boundary vertices are recalculated to approximate the boundary surface more accurately. Mesh adaptivity can be controlled by a feature sensitive error function, the regions that users are interested in, or finite element calculation results. Finally, a relaxation based technique is deployed to improve mesh quality. Several demonstration examples are provided from a wide variety of application domains. Some extracted meshes have been extensively used in finite element simulations.

中文翻译：

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来自体积数据的自适应和高质量四边形/六面体网格划分

本文描述了一种直接从体积数据中提取自适应和高质量四边形/六面体网格的算法。首先，应用自底向上表面拓扑保留基于八叉树的算法来选择起始八叉树级别。然后使用双重轮廓法提取初步的均匀四边形/六边形网格，在不引入任何悬挂节点的情况下自适应地分解为更精细的四边形/六边形。重新计算所有边界顶点的位置以更准确地近似边界表面。网格自适应性可以通过特征敏感的误差函数、用户感兴趣的区域或有限元计算结果来控制。最后，采用基于松弛的技术来提高网格质量。提供了来自各种应用领域的几个演示示例。