Velvet BSDF

Description

../../../_images/velvet.jpg

Example of velvet BSDF

BSDF This BSDF uses an empirical model which fits the back-reflection caused by thin vertical rods or fibers, such as velvet.

Children Nodes

Filter shader diffuse

The spectral diffuse reflectance, or albedo, of the fiber material

Scalar shader sigma

The fiber direction spread, between 0(perfectly aligned) and infinity(spread in every directions). Generally below 1

Parameters

name

type

description

rebounce

real

Parameter controlling the probability for a reflected ray to collide again with another rod. Between 0 and 1

spread

real

Parameter controlling the correlation between neighbor rods directions in case of multiple bounces. Between 1(correlated) and 5(very uncorrelated)

Ocean XML 6.1 example

<bsdf type="velvet" name="bsdf" rebounce="0.8" spread="1.6">
     <filtershader type="uniform" name="diffuse">
             <spectrum type="rgb" name="spectrum" rgb="0.8   0.86    1" gamma="2.2"/>
     </filtershader>
     <scalarshader type="uniform" name="sigma" value="0.2"/>
</bsdf>