On the "renderer" rollout, increase the soft shadows precision (multiplier) to 4.0.This function will correct any soft shadows artifacts caused by the sun position; at cost of some additional rendering time. Note that this parameter works globally. Otherwise the sunlight's shadow samples would have been more adequate.
Increase the "glossy reflections precision (multiplier)" value to 4.5. This function will correct any glossy artifacts, at the cost of some additional rendering time.
Also, change the "sampling quality" to 1/16 samples per pixel and the filter type to "Mitchell", to increase the rendering quality.
It is recommended not go higher (i.e. 1/64), especially when the final output size is already big.
With everything set, one can finally click render to see the final high resolution render, from your machine. (Fig.28a and Fig.28b)
Alternatively, "distributed bucket rendering (i.e. DBR)" or "net render" rendering techniques could be used for those fortunate enough to have additional computers.
Distributed Bucket Rendering
Ensure to use one method or the other, not both at the same time.
Also, one should not use this rendering method for animations. It works best with still images.
All files should be (i.e. FG; bitmaps; file output path etc) in a shared drive (not local drives i.e. C drive, etc).
Open the "render set up", on "processing" rollout, under "distributed bucket rendering" parameters, check the "distributed render" function.
Click the "add" toggle to add the IP address. The "add/edit DBR" host" dialog box should appear.
Type the IP address number followed by ok to close the dialog box.
Keep adding as many as available and allowed.
To edit, simply select one machine at time and click edit.
To monitor the rendering process, simply open the "mental ray message window.
Check all its options (i.e. information, progress, debug (output to file), open on error etc). (Fig.29a)
Ensure that all your files (FG; bitmaps; file output path etc) are in a shared drive (not local drives i.e. C etc).
Also, the "net render" toggle needs to be checked, and click render. The "network Job assignment" dialog box should be prompted.
Ensure that the "include maps" function is enabled; in case there are any bitmaps or mapping coordinates missing.
Click "connect", to see all the available machines in the server. Select the desired machines from the server field name.
On the "server usage" group, choose "use selected" to enable only the selected machines to be used.
On the "options" group, choose the "split scan lines" option, followed by clicking on the "define" toggle. The "strips setup" dialog box should be prompted: set it to pixels; the overlap value to 2; the number of strips to 10 and strip height to 48; and click o.k. to close the dialog box. Click submit to render. (Fig.29b)
Disable the "use map" function and its color swatch to white. This is to make the background color white.
Keep the image "sampling quality" as before 1/16 samples per pixel and "Mitchell" filter.
Finally, turn off the exposure controls and click render.