Sorry..... 中文真系睇唔明, 我 post 番原本既英文 version
The following list highlights the most important changes made in version 3.5 of mental ray:
New final gathering modes
mental ray now has four final gathering modes: "automatic", "multiframe", "3.4", and "strict 3.4". The automatic and multiframe modes have been greatly simplifi ed and do not require control by radii, while usually giving superious image quality. The multiframe mode is specifically designed to avoid flickering artifacts in camera animations. The 3.4 and strict 3.4 modes are provided for backwards compatibility.
Light lists in instances
Light lists have been added to geometric instances to offer a general, more flexible ways to specify lights for illumination, and for finer control over shadow casting. The same material may now use different lights on different geometries. Light lists provide a new, standard method to pass lights to shaders for illumination; they require, however, support in the shaders by using the new light iterators.
Catmull-Clark meshes
Catmull-Clark polygon meshes ("ccmeshes") have been introduced. This subdivision surface type uses Catmull-Clark rules for smoothening and supports polygons with arbitrary numbers of vertices.
Reloading of .mi files for reduced memory consumption
A command line option -reload has been introduced. If this is specified then mental ray attempts to avoid keeping geometric objects read from the mi file in memory permanently, but re-read them from disk as needed. This optimization is not applicable to all scenes and workflows but may save large amounts of memory on certain complex scenes.
Per-face data
Per-face data have been introduced for polygonal geometric objects. Per-face data make it possible to attach arbitrary floating point data to the primitives. An object may also contain per-primitive data information to identify the data attached to the primitives.
String options
Up to version 3.4, options are hardcoded in the .mi syntax and options data structures. It is now also possible to add new string options in a more extensible way as arbitrary name - value pairs, where the name of the option is an arbitrary string, and the value can be of any of a few basic types.
Photon merging
A new, optional optimization of global illumination using photon mapping called photon merging has been implemented. This feature reduces memory consumption in scenes with complex indirect illumination where were many photons must be shot but only few of them contribute to the rendered image, by merging photons in memory which are closer to each other than a user specified distance threshold. Some scenes which previously could not be rendered in sufficient quality due to memory size of the shot photons may be rendered now using this option.
Paint shader library
A paint shader library has been added with shaders for metallic paint.
Information from Mental Images
http://www.mentalimages.com/2_1_1_technical/new-35.html