I. Introduction
In computer graphics, several types of representation of geometric objects are used, each of which, due to its properties, is used in various fields from 3D modeling systems and CAD systems to real-time visualization systems. The main advantages of the function-based representation [1] is the accuracy of representation (this representation is the most accurate of all existing describes the geometry of the object) and the smallest size of the data required to describe the geometry of the object. The disadvantages include the complexity of geometric processing and visualization in real time. Functional methods demonstrate compactness and flexibility in the structural geometry of CSG (constructive solid geometry). Polygon surface setting is, in fact, a piecewise linear interpolation of a surface. The advantages of such a task are the exceptional simplicity of presentation and versatility. After all, a piecewise linear representation exists for any surface. It is also worth noting the small computational cost required for visualization and geometric transformations. The disadvantages are the large size of the database required to store information about the geometry of the surface, and the broken structure of the silhouette of the object, manifested in its visualization. The spline representation surface setting along with the analytical description is mainly used in modeling systems such as AutoCAD, 3D Studio. It is characterized by high accuracy of representation of both two and three-dimensional objects. In visualization systems, such representation of surfaces has not yet found its application as it requires very high computational costs for processing and visualization. There are also a number of specific ways of defining surfaces, in the form of maps, in the form of a set of cross sections or contours, etc. Such primitives are used mainly for the solution of narrowly specialized tasks, are used mainly in programs modeling, and design. Voxel data is used for volumetric visualization.