Characteristics of 3D Solid Modeling Software Libraries for Non-Manifold Modeling

Abstract

In this work, we improved the efficiency and accuracy of our proposed cylinder-based registration and model fitting method of point clouds by terrestrial laser scanners for the as-built modeling of piping systems. Our algorithm simultaneously calculated the scanner parameters and cylinder parameters to avoid the propagation of registration errors and modeling errors. Coarse registration is performed by finding the alignment of the cylinder axes based on the random sample consensus approach and using a hash table. The efficiency of the coarse registration is improved by introducing a three-dimensional hash table. The fine registration and modeling is performed by minimizing the fitting errors of the cylinders as a nonlinear function of the positional and geometric parameters of scanners and cylinders. An iteratively reweighted least squares method is applied to the fine registration and modeling, leading to improved robustness. Moreover, for the modeling of pipes that are slightly bent due to gravity, incident angle filtering of scanned points and cylinder subdivision of the pipes to be modeled are introduced. The efficiency and robustness of the improved algorithm were compared with the previous approach using both artificial and real point clouds. The effectiveness of incident angle filtering and cylinder subdivision was confirmed. The proposed algorithm achieved the level of cylindrical modeling precision required for the renovation work of piping systems.

A Spatial Reasoning Framework Based on Non-Manifold Topology

“…The NMT framework presents a formal and consistent relationship among the multi-dimensional constituent entities. The authors' earlier work (Chatzivasileiadi, Wardhana, et al 2018) identified eight entities, namely (sorted in descending order based on the dimensional complexity) Cluster, CellComplex, Cell, Shell, Face, Wire, Edge, and Vertex. The hierarchy of these entities is shown in Figure 1.…”

“…These plugins wrap the classes and functionalities in the core package, as well as provide two-way mechanisms to convert an entity between the geometric representations in the host applications and the topological representations in the library. In an earlier publication (Chatzivasileiadi, Lannon, et al 2018), the authors have presented workflows to use this library in building performance and structural analyses.…”

Subdivide and Conquer: Adapting Non-Manifold Subdivision Surfaces Method to Represent and Approximate Complex Geological and Reservoir Structures

“…Although their work deserves appreciation as the first steps of using this method in explicit geological modeling, the authors did not explain the practical details of this approach and offered no explanation for the distinction between using spline surfaces and subdivision surfaces in parametric surface-based geological modeling, especially for non-manifold topology. The term 'Non-manifold' has been used to refer to structures that consist of multiple faces sharing one edge or multiple edges sharing one vertex (Chatzivasileiadi et al 2018). These structures need more complex algorithms for the representations (Rossignac and Cardoze 1999).…”

Uma Estratégia De Modelagem Aberta E Extensível Para a Criação De Modelos De Subdivisões Planares Para Mecânica Computacional

“…Não-manifold é um termo da topologia geométrica que significa permitir que qualquer combinação de arestas, vértices, superfícies e volumes existam em um único corpo lógico [37]. Modelos não-manifold têm uma configuração que não pode ser desdobrada em uma peça plana contínua e, portanto, não são fabricáveis e não são fisicamente realizáveis em um único volume [10].…”

“…Existem muitas outras vantagens oferecidas pelo uso de estruturas de dados topológicas, como eficiência e velocidade no processamento das informações e economia no uso de memória. Nos últimos anos diversos trabalhos têm sido publicados, tais como [6][7][8][9][10][11][12][13][14][15][16], aplicando ou otimizando estruturas de dados topológicas em projetos e pesquisas cientificas.…”