DETECTION OF DEFECTS IN THREE-DIMENSIONAL GEOMETRIC MODELS THAT ARE PRESENTED ON THE BASIS OF HALF-EDGE DATA STRUCTURE

Abstract

Digital 3D models are key components in a large number of industrial and scientific sectors, such as product development and production, gaming and simulation, cultural heritage and archeology, medicine, bioinformatics and pharmaceutical sciences. In most cases, visualization is just one of many stages that comprise the lifecycle of a digital 3D model, which are analyzed and processed using advanced algorithms that typically have stringent requirements for the quality and integrity of input data. In practice (for example, with 3D printing), these requirements are often not met in models that come from different sources. Thus, adaptation of imperfect 3D models to such requirements is of great importance. This paper is devoted to the study of the problems of connected data structures, as well as the possibilities of detecting defects when manipulating polygonal 3D grids constructed on the basis of the Halfedge data structure. The research tool is the OpenMesh source library, which implements the research data structure. The main attention of this article is directed at the identification of singular (complex) defects, which are the primary source of inconsistency between the elements that can not be recreated because of the limitations of the internal topology of the data structure and lead to the formation of defects of a new type. The conducted researches are directed on development and realization of the algorithm, the use of which will allow to create models from the initial data with all inherent defects in them, without creating new defects uncharacteristic for the created model. The proposed algorithms will allow to analyze the model for the presence of defects that were not previously supported by this structure, as well as implement the generalized mesh recovery algorithms that are described in this article. The results of approbation of the considered methods confirmed the effectiveness of the proposed algorithms in detecting defects. For a comparative assessment, appropriate tools are developed and the result of their work is presented.