Gonioreflectometer

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A gonioreflectometer is a device for measuring the reflection behavior of a material (mostly for the bidirectional reflectance distribution function / BRDF).

The device consists of a light source that illuminates the material to be measured and a sensor that picks up the light reflected from the material. The light source should also illuminate the area around the material and the sensor should also be able to pick up data from a hemispherical environment around the target. The hemispherical range of motion of the sensor and the light source corresponds to the (at least) four dimensions of the BRDF . The word component "Gonio" also relates to this fact and comes from the Greek gonía , which means "angle" in German.

Various similar devices have been built to obtain data for similar functions. Most of these devices use a camera instead of the light source intensity measuring sensor to obtain a two-dimensional measurement value:

  • a spatial gonioreflectometer to record a spatial BRDF (McAllister, 2002)
  • a camera frame to record a light field (Levoy & Hanrahan, 1996).
  • an unnamed device for recording value for the BTF (Dana, et al. 1999).

credentials

  • Dana, Kristin, et al. 1999. Reflectance and Texture of Real-World Surfaces . In ACM Transactions on Graphics. Volume 18, Issue 1 (January, 1999). New York, NY, USA: ACM Press. Pages 1–34.
  • Foo, Sing Choong. 1997. A Gonioreflectometer for measuring the bidirectional reflectance of materials for use in illumination computations . Masters thesis. Cornell University. Ithaca, New York, USA.
  • Levoy, Marc & Hanrahan, Pat. 1996. Light Field Rendering . In Proceedings of the 23rd annual conference on Computer graphics and interactive techniques.
  • McAllister, David. 2002. A Generalized Surface Appearance Representation for Computer Graphics . PhD dissertation. University of North Carolina at Chapel Hill, Department of Computer Science. Chapel Hill, USA. 118p.