Sunday, February 26, 2012

[How-To] use Minnaert diffuse reflectance for UE3 materials

Minnaert's model is a pure diffuse reflectance model which does not affect the specular reflectance. Therefore it can be combined with any specular model, like phong, blinn, cook-torrance etc.
The special feature about the minnaert model is that it can provide a velvet look by darkening the model along it edges.


Material Setup

The UE3/UDK implementation requires a material with custom lighting:













The amount of darkening is controlled by a paramter which I named as darkening paramter in the screenshot above. This one can have any value equal or bigger than zero. A value of zero means there is no darkening at all and will result in lamberts diffuse reflectance (UDK default).



Comparison

The following screenshots show the affect of different parameter values.

No comments:

Post a Comment