Improvement of accuracy in lighting simulation by flux transfer method

In  this  paper,  we  describe  the  characteristics  of “Luminous Planner” as a general-purpose lighting design tool, and of “LSR(Lighting Simulation Radiosity)”, which is capable of high-precision lighting simulation by taking space reflection into consideration. The “LSR” divides architectural shapes into small polygons and pursues flux transfer in each small polygon. We applied the progressive refinement approach to the “LSR”, required calculation time and memory have been reduced. Further improvement of the calculation method has also enabled handling of intensity distribution of luminaire and transmittance of surface. And calculation accuracy has been enhanced through the use of perspective drawings and scan lines in form factor calculation. Experiment results to confirm the accuracy of calculations are presented in comparison of calculation and measure.