Development of a µBRDF goniospectrophotometer for BRDF measurement on tiny surfaces

A µBRDF goniospectrophotometer has been developed at LNE-CNAM. This device performs traceable BRDF measurement with a measurement surface of 30 µm of diameter. All angular configuration of measurement belonging to the hemisphere are possible. The spectral range is the visible. This device intends to help to progress in the effort to extent the BRDF metrological scale from the centimetre size to micrometre size. Traceable µBRDF measurement are requested today to validate physical based rendering models used in virtual prototyping and to progress in the comprehension of the appearance of natural material like wool, wood, or leather.