Bidirectional reflectance distribution function: Difference between revisions
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In [[radiometry]], the bidirectional reflectance distribution function describes how energy reflecting of a surface is spread over the hemisphere. It is a function of five variables: | {{subpages}} | ||
In [[radiometry]], the '''bidirectional reflectance distribution function''' describes how energy reflecting of a surface is spread over the hemisphere. It is a function of five variables: | |||
* Spectral Location (e.g. Wavelength) | * Spectral Location (e.g. Wavelength) | ||
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Because the BRDF is a function of five variables, it is often characterized by making measurements at a small set of angles and wavelengths and then fitting a mathematical model to the data. | Because the BRDF is a function of five variables, it is often characterized by making measurements at a small set of angles and wavelengths and then fitting a mathematical model to the data. | ||
Revision as of 19:38, 19 December 2007
In radiometry, the bidirectional reflectance distribution function describes how energy reflecting of a surface is spread over the hemisphere. It is a function of five variables:
- Spectral Location (e.g. Wavelength)
- Incident Zenith
- Incident Azimuth
- Exitant Zenith
- Exitant Azimuth
A surface whose BRDF spreads incident energy evenly over the hemisphere is called lambertian or "diffuse". A surface that for a given incident vector reflects all or most energy in to the mirrored direction is called "specular".
Because the BRDF is a function of five variables, it is often characterized by making measurements at a small set of angles and wavelengths and then fitting a mathematical model to the data.