Kaleidoscope configurations for reflectance measurement

Simulations of different configurations of the symmetrical tapered kaleidoscope are performed to assess their merits for measurement of BRDFs and BTFs. The relationship between optimal kaleidoscope layout, and factors such as hardware restrictions and the resolution of the required reflectance function, is derived. The effect on the measurement of the reflectance function of changing these independent variables is examined through the simulation. These experiments highlight issues affecting the measurement of BTFs using kaleidoscopes, and suggest configurations that allow sampling at regular parameter intervals. A number of other kaleidoscope architectures are explored, which offer the benefits of potentially doubling the range of directions that can be sampled, and allowing adaptive control of sample intervals.