Mathematical and programming toolkit of the computer aided design of the   axonometric piping diagrams
  The problem of the automation of the designing of the axonometric piping diagrams include, as the minimum, manipulations with the flat schemas of three-dimensional wireframe objects (with dimension of 2,5). The specialized model, methodical and mathematical approaches are required because of large bulk of calculuss. Coordinate systems, data types, common principles of realization of operation with data and composition of the basic operations are described which are realised in the complex CAD system of the reconstruction of the plants TechnoCAD GlassX. 
Vladimir V. Migunov