Arnold can generate a log reporting all the steps needed to render an image, as well as any warnings and errors encountered by the renderer. This log also provides detailed statistics that are useful for debugging, optimizing and benchmarking renders.

Note that MtoA will save an individual log file for each frame of animation that has been rendered.

Verbosity Level

Specifies the amount of information in the log messages, with Warnings being least and Debug most:

  • Errors (default): Show errors only.
  • Warning + Info: Show warnings, statistics and any info that does not slow down rendering.
  • Debug: Shows all information. Take care when using this mode as render times may increase.


Shows the log in Maya's Output Window (on Windows). On OSX or Linux, if you start Maya from a terminal window, then the log is output to that terminal window (otherwise, click the File check box to output the log to a file).

On Windows, if you start Maya using the Windows Start menu, you may not see the Arnold log in the Output Window. If this happens, you can either start Maya from the command line (and then the Arnold log will show up in the Output Window), or you can enable File logging.


Specifies the output path for Arnold log files. You can use environment variables.

Max. Warnings

Limits the number of warning messages (of a similar type) that are sent to the log.

MtoA Translation Info:

Dumps debug messages from MtoA during IPR updates, etc..


Startup Log verbosity

It is possible to use a Maya Environment Variable to control the log verbosity when loading the MtoA plugin. To do this you must add the following text to the Maya.env file. For example:


There are 4 levels for this logging:

0 Nothing.

1 Warnings and errors.

2 Warnings, errors and infos (how many extensions we register, how many shader nodes are created, what plugin is loaded).

3 Everything.


Note that in order to view the log in Maya's Output Window (Windows) or in the console (Linux), you must first run Maya through the command line or a batch file.

Error Handling

Abort on Error

If set, rendering will stop as soon as an error is detected. This is the recommended setting. In general, you should not ignore important error messages, or you'll risk crashes, rendering artifacts and undefined behavior.

Texture Error Color

Color used to report texture errors.

NaN Error Color

Color used to report NaN's.

Scenes that contain a bad mesh will render green. Scenes that contain a bad shader will render purple.

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