An LED-only BRDF measurement device

Light emitting diodes (LEDs) can be used as light detectors and as light emitters. In this paper, we present a novel BRDF measurement device consisting exclusively of LEDs. Our design can acquire BRDFs over a full hemisphere, or even a full sphere (for the bidirectional transmittance distribution function BTDF), and can also measure a (partial) multi-spectral BRDF. Because we use no cameras, projectors, or even mirrors, our design does not suffer from occlusion problems. It is fast, significantly simpler, and more compact than existing BRDF measurement designs.