Complex Fresnel texture for Cycles

Software:
Blender 2.79 | Cycles Renderer

The most realistic way to create real world metal shaders is to use Complex Fresnel reflection.
Cycles has a general implementation of a Complex Fresnel reflection in its Principled shader (when Metallic is set to 1.0), but this implementation doesn’t allow using real world physical numeric Complex IOR values in order to accurately render physical metals.

You can use a Complex IOR OSL shader such as this one from Chaos Group,
But there are some limitations with it:
1) It isn’t supported in GPU rendering.
2) For some reason I don’t know I couldn’t get it to work with Cycles..

Seeing these limitations I decided to develop a Complex Fresnel/IOR texture for Cycles that will work on GPU, and your welcome to download it here on my studio’s website:
https://cg-lion.com/2018/07/08/free-complex-fresnel-texture-for-blender/

The blend file itself contains a text with some Complex IOR preset values for metals,
And you can get more physical IOR data from refractiveindex.info

Enjoy! ­čÖé

BlenderNation

Related:

  1. Fresnel Reflections
  2. Metallic shading in V-Ray Next
  3. Create rich metal in UE4 
  4. Customizable Photo-realistic Car-paint shader for Cycles

 

Advertisements

Cycles Tangent node & Anisotropic reflection

Software:
Blender 2.79

The Cycles Tangent node defines a Tangent-Space for a mesh by either using one of the object’s local axes or by using an available UV layout.

This can be useful when designing an Anisotropic reflection shader like in the case of brushed, machined or lathed metals.

Examples:
In the first example the Tangent node is set to┬á‘Radial’┬áDirection mode, in which a object axis is chosen as the radial axis of the Anisotropic direction.
In the second example┬áthe Tangent node is set to┬á‘UV map’┬áDirection mode, in which a UV map is chosen as the Anisotropic direction.

Note:
In order to create a special Anisotropic direction you would usually not create a deformed UV layout, but a normal one, and connect a grey-scale texture to the Rotation input of the shader to define changes in the Anisotropic direction on the surface.

Untitled-1

Untitled-2