There are a number of different materials for use with V-Ray for Houdini. These materials are quite versatile and each can be used in a number of ways to achieve different looks as needed from simulating simple surface properties like plastics and metals, to simulating complex uses such as translucent objects, subsurface materials such as skin, and even light emitting objects.
Some basic information on each material can be found below, but for more details, please see the dedicated pages for each one.
Note: Standard Houdini materials are not supported by V-Ray!
