By default, the mental ray renderer understands standard Maya materials. Nevertheless, a large number of mental ray shaders (materials) are provided with the program. You can access the shaders through the mental ray section of the Create tab in the Hypershade window. The shaders are also listed in the Create Render Node window (see Figure 7.1).
You can assign a shader to a surface by choosing Assign Material To Selection through the RMB marking menu in the Hypershade. However, to see the result in the render, you must switch to the mental ray renderer in the Render Settings window. If the mental ray shaders do not appear in the Hypershade, you must activate the Mayatomr.mll plug-in in the Plug-In Manager window.