Map roughness

../../../_images/map1.jpg

Carbon reflective material associated with a map roughness. The isotropic distribution image is shown at the left, it combines a classical gaussian roughness with cone-like structures having slopes around 20°

Roughness The map roughness allows giving a custom roughness distribution as an image, representing the microscopic normal distribution as a function of theta (vertically) and phi(horizontally). The given distribution is automatically normalized.

Theta is the angle between the local, microscopic normal vector, and the macroscopic, or geometry surface normal. It varies between 0° (image top) and 90°(image bottom).

Phi is the angle between the projected local normal and the U tangent space direction. It varies between 0° (image left) and 180° (image right), as the distribution must be symmetric by a 180° rotation.

If the image width is 1, or if pixels in the same rows all have the same value, the roughness is isotropic.

Children nodes

Image map

The surface normal distribution map

Scalar shader zscale

Roughness vertical scaling modifier

Parameters

none

Ocean XML 3.0 example

<roughness type="map" name="roughness">
     <scalarshader type="uniform" name="zscale" value="0.7"/>
     <image type="" name="map" path="distribution.png"/>
</roughness>