Algorithms of reconstruction of 3d wireframe model from drawings

This article describes the issue of automated conversion of two-dimensional technical drawings into three-dimensional wireframe models, a key aspect in the context of digitalization and the transition to paperless technologies in mechanical engineering and construction. Despite significant advances in computer-aided design systems, existing solutions primarily provide a one-way link from three-dimensional models to two-dimensional drawings, while reconstructing three-dimensional models from two-dimensional projections remains a complex inverse problem of descriptive geometry. This paper describes an algorithm for automated processing of projection views, focused on reconstructing topological and metric relationships, based on the use of bounding rectangles to select projection views and projection vectors to reconstruct projection relationship lines. An algorithm for generating a wireframe model is presented based on an analysis of connections between cloud points and edge projections onto projection views. This algorithm accounts for various configurations of supporting lines (lines, ellipses) and expands the class of modeled bodies to objects bounded by planes and quadratic surfaces (ellipsoids, elliptical cylinders, cones). The obtained results allow for a 30-100-fold reduction in design time for objects of various purposes. Experimental implementation demonstrated that a model that takes 40 minutes to construct manually can be automatically reconstructed in 33 seconds.