The increasing reliance on 3D scanning and meshless methods highlights the need for algorithms optimized for point-cloud geometry representations in CAE simulations. While voxel-based binning methods are simple, they often compromise geometry and topology, particularly with coarse voxelizations. We propose an algorithm based on a Series of Local Triangulations (SOLT) as an intermediate representation for point clouds, enabling efficient upsampling and downsampling. This robust and straightforward approach preserves the integrity of point clouds, ensuring resampling without feature loss or topological distortions. The proposed techniques integrate seamlessly into existing engineering workflows, avoiding complex optimization or machine learning methods while delivering reliable, high-quality results for a large number of examples. Resampled point clouds produced by our method can be directly used for solving PDEs or as input for surface reconstruction algorithms. We demonstrate the effectiveness of this approach with examples from mechanically sampled point clouds and real-world 3D scans.@en

Various computational fluid dynamic simulations in engineering, such as external aerodynamics, only need the silhouette of an input geometry. Often, it is a laborious process that can take up many human hours. In addition, the CAD geometries are too complex and contain intricate features and topological holes. We showcase an effortless way to shrink-wrap triangulated surfaces with the sole intent of topology and surface simplification. Building upon the concepts of mathematical morphology and newer advancements in geometry processing, we present a straightforward and robust algorithm that can guarantee genus-zero surfaces. Our techniques are equally applicable to general polyhedral meshes and well-suited for handling both oriented and unoriented point clouds. We provide examples using unoriented point clouds to demonstrate the versatility of our algorithms. We have designed our algorithms with a wide variety of applications in mind. However, we specifically highlight their capability for aerodynamic simulations, fluid volume extraction, and surface simplification. Additionally, we emphasize the practicality and ease of implementing the proposed algorithms, and we chain additional algorithms to develop variants of our wrap algorithm.

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We present a simple and fast algorithm for computing the exact holes in discrete two-dimensional manifolds embedded in a threedimensional Euclidean space. We deal with the intentionally created "through holes" or "tunnel holes" in the geometry as opposed to missing triangles. The algorithm detects the holes in the geometry directly without any simplified geometry approximation. Discrete Gaussian curvature is used for approximating the local curvature flow in the geometry and for removing outliers from the collection of feature edges. We present an algorithm with varying degrees of flexibility. The algorithm is demonstrated separately for sheets and solid geometries. This article demonstrates the algorithm on triangulated surfaces. However, the algorithm and the underlying data structure are also applicable for surfaces with mixed polygons.

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Distance fields finds a lot of applications recently in computational geometry. We propose an algorithm to extract the mean camber line of an airfoil using distance fields. This method does not require computing any geometric approximations in- side the airfoil geometry. It also does not need the airfoil coordinates to be evenly distributed on the top and bottom. All the computations are done on a simple Cartesian mesh and can be easily coupled with any existing computational fluid dynamics codes. We show the efficiency of the algorithm on a variety of airfoil geometries. We demonstrate the robustness and exibility of the algorithm for a wide range of airfoil geometries. @en