Lobe BSDF

Description

../../../_images/lobe.jpg

Example of a lobe BSDF measured on a nacre paint

bsdf This BSDF allows defining custom and measure-based BRDFs where the spectral reflectance is a function of the angle between the reflected ray and a specular reflection.

The lobe child node gives the surface spectral reflectance as a function of the angle between the reflected ray and the specular reflected direction. Light reflected below the material surface at low incidence is re-reflected to avoid unrealistic energy loss.

Note

Using this feature requires an Advanced Edition license

Children Nodes

Angle variable spectrum lobe Angle variable spectrum data corresponding to the reflectance lobe

Ocean XML 3.0 example

<bsdf type="lobe" name="bsdf">
   <avspectrum type="" name="lobe" scale="angle">
      <spectrum type="tabulated" name="#">4E-7 192.2 5E-7 223.4 6E-7 236.9 7E-7 245.3</spectrum>
      <spectrum type="tabulated" name="#">4E-7 1.430 5E-7 1.796 6E-7 1.618 7E-7 1.434</spectrum>
      <spectrum type="tabulated" name="#">4E-7 0.971 5E-7 1.330 6E-7 1.230 7E-7 1.113</spectrum>
      <spectrum type="tabulated" name="#">4E-7 0.627 5E-7 0.943 6E-7 0.888 7E-7 0.824</spectrum>
      <spectrum type="tabulated" name="#">4E-7 0.411 5E-7 0.702 6E-7 0.679 7E-7 0.650</spectrum>
      <spectrum type="tabulated" name="#">4E-7 0.296 5E-7 0.571 6E-7 0.569 7E-7 0.559</spectrum>
      <spectrum type="tabulated" name="#">4E-7 0.237 5E-7 0.514 6E-7 0.518 7E-7 0.519</spectrum>
      <spectrum type="tabulated" name="#">4E-7 0.211 5E-7 0.488 6E-7 0.497 7E-7 0.504</spectrum>
      <spectrum type="tabulated" name="#">4E-7 0.203 5E-7 0.482 6E-7 0.492 7E-7 0.500</spectrum>
      <spectrum type="tabulated" name="#">4E-7 0.200 5E-7 0.483 6E-7 0.492 7E-7 0.502</spectrum>
   </avspectrum>
</bsdf>

The example data was simplified for readability, you can download the full example here : material-lobe.ocxml