INDOOR ILLUMINANCE SIMULATION METHOD

PROBLEM TO BE SOLVED: To solve the problem that it is difficult to preliminarily design a skylight window because light distribution characteristics have been actually measured conventionally per skylight window for actual use and large quantities of kinds of members are currently recommended as optical members for constituting a skylight window.SOLUTION: A peculiar optical characteristic function comprising a bidirectional transmittance function and a bidirectional reflectance function based on actual measurement values is prepared with respect to each tabular optical member, and an optical physical model based on peculiar optical characteristic functions and configuration modes of a plurality of optical members constituting a skylight window constituted by combining the optical members is generated, and the optical physical model is used to calculate skylight window light distribution data of daylight introduced through the skylight window, and the light distribution data is utilized to simulate indoor illuminance obtained by construction of the skylight window. It is simulated by a computer system which has optical characteristic functions per optical member as a database.