Abstract :
The efficiency of computational methods of form factors is one of the main concerns in lighting calculations. Several computational techniques have been developed in the past to improve the efficiency, but for practical applications of form factor computation in lighting calculations, numeric solutions of the double area integral for general perpendicular and parallel rectangle surface cases have been developed and are widely used. The main advantage of form factor computation in lighting calculations is the ability to perform accurate and fast calculations of luminous quantities in architectural spaces.
In this paper, the historical development of the form factor computations and a practical application of DiLauraʹs recently developed form factor computation are introduced, with an analysis of the accuracy of such an application. A computer simulation code is introduced to compute any form factor values for arbitrary surface orientations. A systematic analysis of how the results of a contour integration solution differ from those of existing numeric solutions was also undertaken. Various situations between sending and receiving surfaces were considered, including the facing, size, and distance of two surfaces. In addition, the validation of this developed code was carried out with the principles of the form factor.
