A method to estimate the shading of solar radiation theory and implementation in a computer program

A general method to determine the shading of direct and diffuse radiation is presented. This can handle an almost infinite number building surfaces and screens of any shape. Furthermore, the method can be used to determine view factors in rooms of arbitrarily shape.
A formula to determine the non-shaded area of a surface sunlit by direct radiation at a certain incidence angle is described. This formula is then used in an algorithm to determine view factors used to estimate the shading of diffuse, isotropic radiation. The implementation in a computer program is described and the algorithms used as well as some results are discussed