Additive BSDF



Example of additive BSDF summing measured diffuse and theoretical specular components

BSDF This special BSDF sums other BSDFs. This is often used when a BSDF can be described by a sum of separable components. For instance, a diffuse paint with a very smooth varnish leads to a BSDF which has both diffuse and specular properties. Both properties are not well measured in the same lab tool, and need to be characterized independently. The diffuse part can be measured in a BRDF bench, while the specular part is best described by the varnish refractive index, measured in an ellipsometer.


Using this feature requires an Advanced Edition license

Children Nodes

This node is a bsdf list. It may have a variable number of BSDF children with custom names.

bsdf user-defined

First BSDF

bsdf user-defined

Second BSDF

bsdf user-defined



Ocean XML 6.1 example

<bsdf type="additive" name="bsdf">
     <bsdf type="specular" name="bsdf1" irtrmin_tweak="0">
             <intlaw type="cfresnel" name="intlaw">
                     <dielectricfunc type="na" name="dielectricfunc">
                             <spectrum type="uniform" name="n" value="1.52"/>
                             <spectrum type="uniform" name="a" value="0"/>
     <bsdf type="lambertian" name="bsdf2">
             <filtershader type="uniform" name="diffuse">
                     <spectrum type="rgb" name="spectrum" rgb="0.44  0.28    0.34" gamma="2.2"/>