Max includes a plug-in architecture that lets you replace or extend any part of the software including the rendering engine. Mental ray is a plug-in rendering engine that offers many advanced features. This engine takes the rendering in Max to a new level, enabling you to render your scenes with amazing accuracy. It also includes a host of advanced rendering features including caustics and global illumination that are physically realistic.
If you're accustomed to using the Default Scanline Renderer and you're wondering if the mental ray rendering engine is good for you, the answer is yes. Actually, you should try a couple of test renderings first and play with the different settings, but in working with mental ray I've been amazed at its results. One of the chief benefits of mental ray is its speed. It can render a fully raytraced scene in a fraction of the time without sacrificing quality.
mental ray is an external rendering engine that plugs into 3ds Max. It was developed by a company named mental images, so its development is separate from Max. Versions of the mental ray rendering engine also can be found in Maya and Softimage as well as a stand-alone version.
mental ray also includes support for global illumination without your having to enable the Advanced Lighting settings. ...