Back on the "indirect illumination" rollout, pan down to the "reuse (FG and GI disk caching)" rollout.
Change the final gather map type to "incrementally add FG points to map files. This function will calculate and save all the final gather points.
Click on the file toggle to set the name and destination of the saved FG file. Save it in the network preferably...as mentioned earlier. The adjacent button(X) enables the user to delete any existing file in the written destination.
Since we know the overall result of the render, it's wise to enable the "calculate FG/GI and skip final rendering function, if desired. This function forces mental ray to compute the Fg process only, skipping the rendering. Some users prefer to see the final result.
Finally, click the "generate final gather map file now", to render. Or alternatively press shift + Q. (Fig.22a and Fig.22b)
Once the rendering process is finished; change the final gather map type from "incrementally add FG points to map files" to "read FG points only on existing map files". This will freeze and reuse the FG map.
Also, lock/freeze the cashed geometry from "geometry caching" function. (Fig.23)
Mental ray is quite powerful in producing glare; camera depth of field and chromatic aberration effects straight from the renderer however, in this exercise we will use 3Ds Max's rendered elements to facilitate adding some these effects in Photoshop.
The first element to setup is the Z depth. This element will help to add the camera depth of field in Photoshop, if required.
It is prudent to setup its parameters prior to sending the final render:
In the "render elements" rollout, click the "add" button to open the render elements dialog. Choose the "Z depth" element from the list (Fig.24).
The "enable" function needs to be checked.
By default, its file destination path is the same as the render output file.
The min and max Z values are set from 100 to 300 by default. Tweak and test render with its settings to see what suits best.
It is worth mentioning that one can increase the original Z Depth contrast in Photoshop (i.e. with curves/levels) to expand darker/brighter areas. (Fig.25)
Material and object's Ids elements are equally crucial when sending out the final renders; especially when one is required to address changes quickly. (Fig.26)
One should start tagging the objects and materials from the start of the project; as objects and materials can quickly grow to unmanageable numbers.
Once satisfied with most parameters, one can begin to prepare the scene for final rendering.
On "common" rollout set the final output size to 3500x1638 pixels. Note that there was no need to render higher resolution, as the render is looking very sharp and without noise.
On "render output" group, click on the "files" toggle to choose the file location and format.
This new location will subsequently alter the original rendered elements location.
I personally use "Targa Image file" formats, since all the extra rendered elements are being saved however, a growing number of users are choosing ILM's "OpenEXR image file" format.
Note that, when opening these files in Photoshop, one will be required to turn its default 32bits/channel mode to 16bits or lower in order to utilize some of the Photoshop's filters and layer adjustments. (Fig.27a and Fig.27b)