Here you can define the number of Render Threads (number of render lines in the view/Picture Viewer). Defining multiple threads on a single processor system does not make much sense since performance would suffer and the threads can be allotted different amounts of render time (unequal allocation in the Viewport).
If this option is disabled, the number of Render Threads required for a particular processor, or number of processors, will be used.
It can also be quite useful to leave one or more processors (if present) available for third-party applications during rendering. This will, for example, let you use three of four processors on a quad-core system for rendering and the remaining processor for other tasks.
If this option is enabled, Cinema 4D will be given a lower priority by your computer’s operating system, i.e., Cinema 4D will be allotted less calculation time. This can slow the render process but you will be able to work with other applications simultaneously (e.g., text editing, image editing, web browsers, etc.).
If this option is disabled, Cinema 4D will be given a higher priority by your computer’s operating system, i.e., Cinema 4D will be allotted more calculation time. This will speed up rendering but other applications running simultaneously on your computer will have slower reaction times because they will be given a lower priority by your computer’s operating system.
This option is enabled by default and lowers the priority of the Cinema 4D processes (set by the operating system). Also, the render thread priority will be reduced even further than by the aforementioned Adapt Thread Priority option. This minimizes Windows issues (such as freezing) when high demands are placed on the CPU.
This option should be disabled if you simultaneously have programs running that also require a lot of CPU power and can slow down Cinema 4D and in turn slow rendering. The render process will be allotted more power (to the disadvantage of other applications).
If this option is enabled, a file named RENDERLOG.TXT will be created (if one does not already exist) in the Cinema 4D directory after an image has been rendered.
The render log contains a complete history of the render process, including system resource information. Check this log if you need to identify problems that occurred while rendering.
If a Log file already exists in the Cinema 4D directory, new information will be added to the end of the file.
An example of a Log File’s contents:
*** RENDER LOG FILE ***
Renderjob started on 06/07/2013 at 11:14:58
File: C:\Documents and Settings\o_becker\Desktop\12.0 Materials\flabio.c4d
Creator: Oliver Becker, MAXON
Cinema 4D V12.003
Serial number: xxxxxxxxxxxxxx
Field rendering: Off
Motion Blur: Off
Volume effects: On
Alpha channel: Off
Output format: Single frames
Render time: 00:00:00
Render job finished on 06/07/2013 at 11:14:58
If enabled, detailed information regarding the GI calculation will be displayed in a Console Window. This information is not of much interest to you and serves primarily for software debugging.
Enable this option if you want the Picture Viewer to save a log file (will be in XML format).