Finding lighted surface parts of polygonal surface in parallel light flux

In this paper a problem of finding lighting surface parts with mutual shading effects is considered. A new algorithm is presented, which is development of algorithm from [1] and uses the quantitative invisibility characteristic [2]. Proposed algorithm is based on positional relationship analysis of contour cycles. Contour cycles confine connected areas, which contain potentially lighted faces. Processing of all singularities is considered in details. Also several stability and optimization issues of program implementation are discussed.
Implementation of this algorithm is used in program pack for calculations of main vector and main moment of light pressure force, which affects on spacecraft with arbitrary shape [3]. Considered algorithm provides with effectiveness and accuracy increase.