amie Cardoso is an author and independent technologist. He volunteered this look at the new mental ray 3.8 and its use in 3ds Max 2011.
The standalone mental ray 3.8 is fully equipped with numerous powerful features such as Iray rendering mode; stereoscopic rendering; IBL mode, etc. However, while some of these new features are not yet fully integrated with 3ds Max, and others are only available via the command line or via plug-ins such as ctrl_ghost_settings.
Actually, some of the existing parameters of the ctrl_ghost_settings plug-in are still being optimised. Finally, Pro materials’ shaders currently being used in earlier versions of Max are now automatically replaced by the new standard Autodesk shaders, when opened with Max 2011.
杰米卡多佐是一位作家和独立的技术专家。他主动介绍了mental ray 3.8在3ds Max 2011的使用
独立的mental ray 3.8是配备了众多强大的功能，如Iray渲染模式，立体渲染IBL的模式，等等不过，虽然这些新功能有些尚未完全与3ds Max整合，有些则是通过唯一可用命令行或通过插件如ctrl_ghost_settings插件。
其实，现行的ctrl_ghost_settings一些参数插件仍在优化。最后，Pro materials取代早期的材质成为欧特克的默认材质,MAX 2011就是使用这种材质
The following discussion will focus mainly on the mental ray 3.8 features that are currently integrated with 3ds Max 2011, and few of the ‘ctrl_ghost_settings’ features that can be implemented for production.
Although the ctrl_ghost_settings for 3ds Max 2011 come with additional features supported by mental ray such as Final Gather; Image Based Lighting; progressive rendering; Iray; Ambient Occlusion Cache; etc, most of them are still being optimised, fixed and/or not fully integrated. Currently, the features that users may find quite useful for production are the importons and irradiance particles.
虽然3ds Max的2011年ctrl_ghost_settings提出，mental ray支持附加功能比如：Final Gather; Image Based Lighting; progressive rendering; Iray; Ambient Occlusion Cache （这也不翻译了，理由同上 呵呵）等等，其中大多数仍在优化，或者是不完全的集成进来（就是说MAX还没有完美的集成MR，我的理解是要向使用全部功能还得使用独立版本，瞎说的 不知道是不是这样）。目前，该功能，用户可能会发现生产中有不少地方用到importons and irradiance particles。
Importons: The Importons emission takes place during the pre-rendering time, and it helps to improve the rendering quality and performance/speed, by providing mental ray with vital information to process its calculations intelligently and resourcefully.
Irradiance Particles: Irradiance particles are collected after the importons are shot from the camera. They preserve the information of both direct and indirect illumination for the rendering process. The direct and indirect illumination information is determined by the number of passes. For production, the importons and irradiance particles can be quite an asset when used simultaneously and cached.
In order to cache the file, the user is required to type in or paste the location/destination to where the file will be saved; followed by its name. The ‘interpolate’ function also requires it to be set to ‘Always’. The first render may take a while to process. However, the subsequent render times will be improved dramatically. It is common practice to cache the file at smaller resolution such as 600×450, and later render it at higher resolution (i.e. 5,000×3,750px).
Irradiance Particles: 是从摄像机收集 importons（~%~没看明白？）他们保存渲染过程中的直接和间接照明的信息。直接和间接照明的信息取决于传球次数。对于生产，importons 和Irradiance Particles可以同时使用，作为共同的缓存
使用缓存文件的话，用户需要指定或者粘贴保存的路径。该文件将被保存。其次是它的名字。在”interpolate’ （差值选项）也需要设置为’Always‘。第一次渲染可能花费的时间会多些。不过，随后的渲染时间将会显着改善。它通常的做法是在较小的分辨率保存缓存 文件，如600×450分辨率，后面在更高的分辨率渲染成品（即它的X3 5000，750px）。
Environment Evaluation: When enabled, the irradiance calculation also takes into consideration maps applied to the environment map slot. This particular function computes IBL files (Image Based Lighting) more accurately by enabling diffused and direct shadows to be cast, depending on the IBL information. The Irradiance particle computation processes indirect illumination far better than the current Final Gather solution. Moreover, it doesn’t require any additional light source in order to be fully functional. Therefore, its irradiance computation can be quite time-consuming, unless it is cached, as mentioned earlier.
环境计算：当启用时， 光度学计算irradiance calculation也要考虑到环境贴图，（我的理解就是环境贴图会影响到计算） 这种特殊的功能通过使计算扩散和直接的阴影（基于图像的照明） ，根据IBL信息更准确的产生阴影。这种Irradiance particle 的计算远远优于当前的Final Gather 最终聚集的计算。此外，它不需要任何额外的光源，才能充分发挥作用。因此，它的照度计算可以很耗费时间，除非它被缓存，如前面提到的
It is worth noting that when the environment evaluation is cached, its indirect shadows may not be as accurate as otherwise. However, the rendering times may drop by more 75% at times; and its quality will still remain superior to any final gather solution. The render [above] had originally taken over three hours with numerous light sources such as daylight system, mr_sky_portal, photometric lights with final gather cached. That having been said, the same image had taken less than 45 minutes, with daylight system, importons and irradiance particles cached. The IBL file was applied to the ‘environment/reflections’ shader, of the ‘environment/background switcher parameters’.‘
值得注意的是，当环境的计算是被保存，其间接的阴影可能不会像其他准确。然而，渲染时间可能下降 75％，有时更多，而且它的质量仍然优于任何最终聚集的解决方案。如果一开始计算大量的光源。如昼灯系统，mr_sky_portal，光度光源与缓存 最后需要3个小时 话虽如此，相同的效果已不到45分钟，日光系统，importons和辐射粒子，缓存。 IBL的文件被应用到’环境/反射SHADER，环境/背景切换参数 。
Color override/ray type Switcher parameters
This fully integrated mental ray shader for 3ds Max 2011 provides users with an array of options to override the eye rays; transparency; reflections; refraction; shadows; final gather; photons and environment. This shader is accessible from the ‘material/map browser’ dialog box list.
这充分整合针对3ds Max 2011提供了几种选择，可覆盖眼睛射线阵列的用户;透明度;反思;折射的mental ray渲染;阴影，最终聚集，光子和环境。上图是这个命令的位置。
The ‘Default’ toggle sole purpose is to retain the basic parameters of the original shader.
Users may find the following useful:
Eye Rays: Only overrides/replaces the color/texture of the relevant surface. Note that these changes do not affect its surface when reflected from a different object.
To also override its original color/texture when reflected on other surfaces, one is required to copy and paste/ instance the eye rays’ contents onto the ‘Reflections’ toggle.
When used for surfaces, users often apply the ‘object color’ and/or the ‘Ambient/Reflective Occlusion’ shader. It’s worth noting that the eye rays function can also be plugged to the ‘environment map’ toggle, especially when using IBL files.
使用表面这个参数，用户经常运用”object color’ ao的SHADER。值得一提的是EYE RAY的方式也可以插入到’环境地图’一栏，尤其是IBL的文件时使用。
Reflections/Refractions: This function only overrides/replaces the color/texture of the relevant surface.
Final Gather: This function only overrides/replaces the Final gather contribution of the relevant surface’s color and/or texture. This function is quite useful to eliminate color bleeding from surfaces.
Photons: This function only overrides/replaces the Global illumination contribution of the relevant surface’s color/texture. This function is also quite useful to eliminate color bleeding from surfaces. As mentioned earlier, all the ‘Color Override/Ray Type Switcher Parameters’ functions can also be plugged to the ‘environment map’ toggle, especially when using IBL files.
光子：此功能仅覆盖/替换有关表面的颜色全球照明贡献/纹理。这个功能也相当有用以消除表面颜色溢出。如前所述，所有的”Color Override/Ray 切换参数的功能也可以插入到’环境地图’切换，尤其是IBL的文件时使用。
Kelvin Temperature Color
This newly integrated shader for 3ds Max 2011 helps to boost and define the correct color temperature of a light source, surface color and/or a texture. It’s common practice to plug this shader onto the ‘mr Sky portal’ custom toggle, in order to be used as a light card for interior scenes independently from a daylight system and/or a ‘Skylight’ object. This shader can be easily accessed from the ‘material/map browser’ dialog box list. Followed by dragging and dropping the shader onto one of the “material editor” dialog slots, in order to edit its parameters.
这针对3ds Max 2011新集成渲染有助于校正和定义一个光源，表面颜色和正确的颜色温度/或纹理。这是常见的做法，以堵塞到’MRSky portal”这个自定义切换着色，以作为一个室内场景从白天光线卡制度和独立/或一个’天窗’的对象。这着色器可以很容易地访问从’材料/地图浏览器 的对话框列表。其次拖放到的“材质编辑器对话框插槽之一”着色，以编辑它的参数。
Kelvin Temperature: This function sets the numerical measurement of the color appearance. The value of 6500.0 represents a bright/cool color.
Intensity: This function sets the brightness of the color temperature.
Finally, when used with ‘mr Sky portal’, it can also help to emulate recessed lighting patterns. The images below clearly depict its results.
Ray tracing Performance
The BSP2 raytrace acceleration method now juggles more efficiently between memory usage and rendering speed, especially when working with assemblies as part of the 3D content.
mental ray render message dialog box
The new mental ray render message dialog box is now divided into three tabs: Production; Material Editor and Active Shade. This new dialog provides users with far more detailed information of the rendering process than before. Some of its rendering information is only available by clicking on its information field, right clicking and enabling its visibility from pop-up menu list.
Click to enlarge
Click to enlarge
Through the ‘map to material conversation’ shader, users can now use MetaSL shaders in 3ds Max. The ‘map to material conversation’ shader essentially converts the MetaSL shader tree into a material that 3ds Max can read. This methodology saves users from using any external compiler. However, the MetaSL shader needs to be saved as a ‘phenomenon’ from mental mill. The ‘Illumination Phong Phen’ serves as one of the basic shaders (i.e. phenomenon) from which MetaSL tree could be built using 3ds Max 2011.
One can also export a single or a combination of mental ray shaders from 3ds Max 2011 to mental mill as XMSL. This export functionality is only available on ‘slate material’ mode. To export the shader simply double click on the relevant sample slot of the slate material editor, followed by selecting the ‘material’ rollout and choosing the ‘Export As XMSL file…’ tool, from the drop down list. It is worth noting that if the relevant sample slot is not double clicked; the ‘Export As XMSL file…’ tool will be disabled (i.e. greyed out)!
The following are the current available MetaSL shaders for 3ds Max 2011:
Conversion Color to Float;
Conversion Float to Color;
Math Color Add;
Math Color Mix;
Math Color Multiply;
Normals Make Normal
Texture Lookup 2D;
Tip: The component Falloff works best when applied in the diffuse channel of a basic shader such as ‘Illumination phong phen’, etc. Using the ‘Normals make normal’ shader in the ‘normal’ toggle of the ‘Illumination phong phen’ will help define its diffuse.
Depth of field/bokeh
Bokeh is the manner in which the camera lens renders the out-of-focus points of brightness/light. Its effect is often more apparent in regions of the image which has specular highlights, light sources, etc. However, its overall blurring effect occurs in all out-of-focus areas of the image. This shader can easily be accessed from the ‘camera shaders’ group; by clicking on the ‘Lens’ toggle and choosing the ‘Depth of Field/Bokeh’ shader from the list.
Focus Plane: Determines the depth of field areas of the camera.
Radius confusion: sets the amount of blurriness.
Samples: Helps to define the blurriness. Higher values yield better (i.e. less grainy) depth of field results, at cost of increased rendering times.
Bias: This function helps to define the shape of the bokeh effect (the value of 1.0 is uniform). Values above 1.0 will distort its uniformity.
Blade Count: This function sets the number of angles of the bokeh. The more counts one uses the greater the rounded effects.
Blade Rotation: This function rotates the bokeh in one spot. The image [above] is an exaggerated illustration of its effect (with mr_glare), directly from 3ds Max Design 2011 and mental ray 3.8. It is worth noting that this effect may be quite time consuming when rendered, but the result is worth it.