A reflectometer setup for spectral BTF measurement

Daniel Lyssi
In proceedings of CESCG, Apr. 2009
 

Abstract

In computer graphics, information about a material’s reflectance properties is needed to visualize it correctly in a virtual scene. A common representation of these properties is the BTF (Bidirectional Texture Function). Ideally, the BTFs should be available in a spectral form (more than 10 non-overlapping wavelength bands) to allow for correct colour calculations. Currently, however, all BTF measurement methods rely on RGB cameras or similar tristimulusbased devices. Reasons for this are the large amounts of data generated by spectral measurements, which would have been too much to handle just a few years ago, the long measurement times and the enormous cost of specialized hardware needed for a spectral acquisition. Since RGB values are not sufficient for the correct reproduction of a material’s visual appearance under arbitrary lighting conditions, we now present a measurement setup for the acquisition of spectral BTFs.

Keywords: BTF, material measurement, spectral

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Bibtex

@INPROCEEDINGS{lyssi-2009-btfspectral,
        author = {Lyssi, Daniel},
         title = {A reflectometer setup for spectral BTF measurement},
     booktitle = {CESCG},
          year = {2009},
         month = apr,
  howpublished = {To appear in Proceedings of CESCG},
      keywords = {BTF, material measurement, spectral},
      abstract = {In computer graphics, information about a material’s reflectance
                  properties is needed to visualize it correctly in a
                  virtual scene. A common representation of these properties
                  is the BTF (Bidirectional Texture Function). Ideally,
                  the BTFs should be available in a spectral form (more than
                  10 non-overlapping wavelength bands) to allow for correct
                  colour calculations. Currently, however, all BTF measurement
                  methods rely on RGB cameras or similar tristimulusbased
                  devices. Reasons for this are the large amounts of
                  data generated by spectral measurements, which would
                  have been too much to handle just a few years ago, the
                  long measurement times and the enormous cost of specialized
                  hardware needed for a spectral acquisition. Since
                  RGB values are not sufficient for the correct reproduction
                  of a material’s visual appearance under arbitrary lighting
                  conditions, we now present a measurement setup for the
                  acquisition of spectral BTFs.}
}