Lobe material

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Example of a lobe material measured on a nacre paint
material-2014.png

Description

This material 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 material 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.

Children nodes

node-2014.png lobe
Angle variable spectrum : Angle variable spectrum data corresponding to the reflectance lobe
medium-2014.png bulk
Medium : The bulk medium filling the geometry volume on the back side
normalshader-2014.png bump
Normal shader : Normal shading modifier
emitter-2014.png emitter
Emitter : The Surface light emission properties

Ocean XML 2.0 example

<oceanroot version="2.0">
<material type="lobe" name="previewmaterial">
	<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>
</material>
</oceanroot>

The example data was simplified for readability, you can download the full example here

See also

Material types