Bidirectional reflectance definitions

Products from cars, to cosmetics, to paper depend upon sophisticated visual effects - colour, gloss, transparency, texture - for commercial success.  Considerable R&D goes into creating metallic paints, pigments, finishes, sparkle and grainy effects. Commercial devices using Bidirectional Reflectance Distribution Function (BRDF), a reflection technique suitable for measuring sophisticated visual effects, have recently been developed. Primary references and calibration artefacts for these have been established at NMIs, but there remains a lack of BRDF standards.

The project has used results from EMRP project IND52 xDReflect to carry out BRDF measurements on different visual effects and independently validated them, and used these measurements to propose standards and guidance, as well as agreed formats for measurement data. It has made recommendations for the characterization of surface gloss, sparkle and graininess effects and agreed new approaches for measuring these. Standardised approaches to BRDF will help manufacturers produce a new generation of instruments, giving many industries, including automotive and cosmetics, better control of product appearance and higher customer satisfaction.