Lobe BSDF¶
Description¶
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¶
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