By now most of us have probably heard of the new Cycles render engine, which will bring a long overdue upgrade to our Render Engine. While Cycles's rendering capabilities rival those of Luxrender and other external renderers, and is much faster, its materials system is entirely new and has done away with many of the sliders and options that we have come to know and love in Blender Internal. Aside from an annoying, tiny, cramped font, the new Cycles Materials can be confusing and intimidating, so I've made this tutorial covering all the new settings you'll find in Cycles.
Don't have Cycles? Grab the latest build off of Graphicall.org!
-Note from the Author- This is a pretty old tutorial Blender-wise, and may not be entirely accurate.
Diffuse is your basic, Clay render material. While it can be boring, it's very useful for adding some shading to other materials when mixed, which we will get to later.
Color controls the color of the material. A texture can be added by clicking the tiny button. A dropdown menu will give choices for a variety of Procedural Textures.
By default, it's already set to an RGB texture. The RGB texture simply gives a solid color to the material.
Procedural textures can be added like this clouds texture. They can be edited right in the Materials Panel too. It's been oversimplified in Cycles, but the basics are still there. Instead of being assigned influence values, textures are given to settings to control their value. In other materials, textures can affect the fresnel, roughness, etc.
Image textures can also be added, however there is currently a bug in Cycles. If you try to add an Image texture, an old friend will drop by for a visit:
A fixed version of cycles has now been released on Graphicall. Image Textures now work.
The glass material is a refracting, transparent material.
Roughness controls how glossy the Glass is.
Fresnel controls how "Defined" the Glass is, and how much it refracts light. At Zero, the Glass does not refract anything, and its transparency is determimned by how many layers of mesh the light ray travels through.
Fresnel at a higher Value results in more defined glass and more refraction.
Glossy is a shiny, reflective material.
Roughness controls how glossy the material is. At zero, you get a very shiny material.
However, at higher values, you get a more matte shading.
Fresnel determines how bright the reflection is or how much of the original light is reflected back. At 1, the object is completely reflective.
Shading methods like "Sharp" have no noticeable effect on the material.
Transluscent shading results in a rough wax-like material, which allows light to pass and scatter through and illuminate the opposite side.
Transparent materials are Transparent, with no Refraction or Fresnel.
Transparent materials are nearly shadeless, lack fresnel, and their alpha value is the same throughout the material.
Velvet is a Fresnel Shader which lightens the edges, and causes light rays to bounce in every direction when striking the mesh.
Emission is self describing. Cycles uses object based lighting along with Blender's internal lamp system, so the emission material turns an object into a lamp.
The strength determines how bright the object is.
Hmm. For once there isn't a Fresnel setting. :P
Mix Closure creates two slots for two new materials, a.k.a. closures.
You can even make the materials in the slots "Mix Closure"s and make an even more complicated material.
This Mix between a Diffuse and a Glossy creates this nice, glazed Ceramic material.
Anyone who's ever done any compositing knows that "add" means to add two values to produce a stronger or brighter result instead of averaging them out. That's what "Add Closure" does.
Background, Volume, and Displacement
As far as I know, Volume and Displacement are still placeholders, and don't work yet. Background will only work if it's given to the World Panel.
There are also nodes known as Light paths. More info can be found here.