Using Cycles Materials
First, you need to understand that in Cycles, a material is made up of shaders. You have different shaders from which; each one of them has different properties from real materials and you’ll have to mix those properties together to create your own materials. Before you start diving into shaders and how to mix them, take a look at Figure 10.7 to see how the Material tab looks when you use the Cycles render engine. It’s very different from Blender Render’s Material tab!
At first sight, this menu may look simpler than Blender Render’s menu, but here’s the difference: in Blender Render, all the settings are visible to you from the start; with Cycles, the Material panel is very basic to begin with, but you can extend it in order to create complex materials as you add more shaders. Let’s very briefly discuss the panels you’ll find on this Material tab:
Current selection, materials List, and current material: The first three panels on the Material tab are exactly the same as those in Blender Render. They show the current selection, a materials list that allows you to use different materials inside the same object, and a menu where you can select a material that you have previously created, rename it, or create a new one. (The menu shown in the image is the one that appears after you click the button to add a new material.)
Preview: In this panel, you have a material preview, almost the same as the one in Blender Render, although you’ll notice this one will update little by little and, at first, you might get some noisy results. This happens because Cycles is a progressive rendering engine; when the number of samples is low, you’ll get noise that will clean up slowly as more samples are added to the rendered result.
Surface: This is the main panel of the Cycles Material tab where you select the type of shaders you’re going to use and their properties. You’ll learn about shaders in the next section.
Volume: This panel was added in Blender 2.70 and it allows you to apply volumetric effects to the objects that use this material. Volumetrics is the technology that simulates such things as fog, smoke, and gases, and it’s very useful for adding ambience to a scene. This material lets light pass through it to create cool effects. Unfortunately, this is the first version and, while it does work, it’s very slow and has some limitations.
Displacement: This panel allows you to use a gray-scale (height map) texture to deform the surface of a mesh so that it has much more detail. When you displace a material in Cycles, you can also load normal maps and bumps. However, using this feature is kind of tricky because it’s still under development and it requires advanced knowledge to edit the nodes properly. Alternatively, there is a modifier you can apply to the mesh to use displacement, but working with it is really slow because you have to subdivide the mesh a lot to make it work properly.
Settings: In this panel, you’ll find some more options for the material such as its color in the 3D View, the Pass Index (to separate elements in the Compositor), and enabling the material to receive transparent shadows.