Analysis of johnson polyhedra using projective geometry techniques ПРОЕКТИВОГРАФИЧЕСКИЙ АНАЛИЗ МНОГОГРАННИКОВ ДЖОНСОНА

The authors analyze the capabilities of projective geometry techniques based on the method of tracing for diagrams, as applied to problems of Johnson polyhedra and formation of convex polyhedral structures. Johnson polyhedra, known as Johnson solids, demonstrate a specific type of symmetry. Each polyhedron can serve as the core for varied shapes capable of preserving their properties. The authors believe that the research into clusters of Johnson solids have a stronger potential than any research into a single Johnson polyhedron. The paper shows how the change of parameters (rotation angles, axis of symmetry, and number of facets) can be preserved for a variety of shapes; this is a very lucrative property in terms of architecture and design. Specialized computer software is used for the practical implementation of the method.<br>Проведен анализ возможностей проективографического аппарата, основанного на методе следовых эпюров, в применении к многогранникам Джонсона в задачах формообразования выпуклых многогранных структур. Рассмотрены многогранники Джонсона, для которых указаны типы симметрии. Каждый многогранник может являться ядром одноэпюрной или многоэпюрной системы. Показано как при изменении параметров (углов поворота, осей симметрии, количества ядер) можно получать многообразие форм, интересных с точки зрения архитектуры и дизайна. Для практической реализации метода применена специально разработанная компьютерная программа

On the use of polar coordinate system in the projective graphic drawings

Projective graphics is a polyhedra simulation method, which is based on the use of trace diagrams of initial polyhedron. Previously developed computer software allows using Cartesian coordinates. In some cases it is advisable to use polar coordinate system for description of projective graphics drawings. Using the example of icosahedron the authors analyzed the advantages of using projective graphics drawings in the polar coordinate system. The transition to the polar coordinate system is a tool that allows using certain patterns of projective graphics drawings in the process of calculation. When using polar coordinate system the search of Polar correspondence for the directs is simplified. In order to analyze the two lines in the polar coordinate system it is enough to compare the corresponding coefficients of the equations of these lines. The authors consider a diagram of the icosahedron in polar coordinates, and a corresponding fragment of calculation program in the Mathematica system. Some examples of forming based on icosahedrons are offered. Optimization of computer programs using polar coordinate system will simplifies the calculations of projective graphics drawings, accelerates the process of constructing three-dimensional models, which expand the possibilities of selecting original solutions. Finally, the authors conclude that it is appropriate to use the polar coordinate system only in the construction of projective graphics diagrams of the planes system having rich symmetry. All Platonic and Archimedean solids, Catalan solid possess this property

Automatic receipt of projective geometry drawings of Johnson bodies

The article analyzes the possibilities of polyhedral structures’ formation basing on the automated construction of orthographic drawings (trace diagrams) derived from Johnson bodies. Projective Graphical method makes it possible to simulate the new multi-faceted forms with the help of the trace diagrams selected as a basis of a polyhedron. The computer program developed for this aim allows receiving both trace diagrams and diverse visual images of newly created polygonal shapes. Due to the large number of possible solutions it is proposed to use trace diagrams themselves (based on their degree of symmetry) as a tool to assess the feasibility of using this or that Johnson body as a basis for further shaping