Abstract
This paper presents some Monte Carlo simulations for the calculation of illuminance of interiors including the component caused by reflected light. The authors at first argue about what the necessary and sufficient condition is with regard to Monte Carlo simulations for the calculation. In this paper, the condition has been translated into a different expression so that it may be conveniently applied to the simulations for reflected luminous flux from surfaces of interiors. After showing the condition, the authors give some newly-devised simulations togetter with a conventional one, discuss their validity, and compare advantages and disadvantages among them.
