Graphics Reference
In-Depth Information
11. Exit Edit Mode by pressing
Tab
. Rename the group
Metal
. Although this is not
"strictly necessary here, you can also click on the F icon on the interface to
activate the
fake user
for the node group.
12. Save the file as
Metal_group.blend
.
How it works...
The effect of this node group is mainly based on the IOR value (the refractive index of a
material is a number that describes how light propagates through that material or gets
reflected on its surface). This value can be quite different for each kind of metal. In the
node, the exposed IOR value drives the amount of blending of the Diffuse component with
the Mirror component made by the Glossy BSDF and Anisotropic BSDF shader nodes
combined, but that can also be mutually blended accordingly to the Aniso_Amount value.
The Anisotropy and Rotation values of the Anisotropic BSDF shader are exposed as well.
and the same for the Tangent input if a particular mapping option must be used (for example,
a layer of UV coordinates).
Textures must be connected to the Bump input socket on the Bump node. The Bump_Strength
socket establishes the amount of bump influence. The Bump_Distance socket is a multiplier for
the strength of influence. The Bump node output is piped to all the Normal input of the Fresnel,
Diffuse BSDF, Glossy BSDF, and Anisotropic BSDF nodes to keep a consistent effect among
all the components. Similarly, both the Glossy BSDF and Anisotropic BSDF nodes' Roughness
values are driven by a single-interface input.
Finally, let's discuss the color of the metal. The color that arrives at the Diffuse BSDF shader
by passing through the Bright/Contrast node gets modified by a Coated value larger than
0.000
. The result is a different input for the mirror component. The Subtract-Math node
simply inverts the effect of the numeric input of the Coated socket.
Besides the links provided at the end of the previous chapter, for a list of IORs, you can take
a look at these links:
Note that for some materials (especially metals), different lists report
different IOR values.
