This description is for the Arnold Standalone to render .ass files (with kick).

(It is not a description how to setup/render Maya/Houdini scenes with Arnold enabled)

Setup 

By default Arnold is configured to use a Shared Executable.

• Create the folder        [RR]\render_apps\renderer_exe\arnold\win_x64\Arnold-4.0.6.0\
  Change the Arnold version and OS to match your environment. (Arnold version, not MtoA version)
  If you do not know the Arnold version, please load a .ass file into the rrSubmitter. It will show the version in the lower left.
• Copy the contents of your Arnold Standalone/MtoA/KtoA... folder into this new folder
• If everything is setup right, then you find the kick executable in  [RR]\render_apps\renderer_exe\arnold\win_x64\Arnold-4.0.6.0\bin\kick

Setup - Houdini / HtoA .ass files

By default, HtoA has the kick executable not in /bin, it is in /scripts/bin

Therefore we have created a second render config for rendering with HtoA.

• Create the folder        [RR]\render_apps\renderer_exe\arnold\win_x64\HtoA-4.0.6.0\
  Change the Arnold version and OS to match your environment. (Arnold version, not HtoA version)
  If you do not know the Arnold version, please load a .ass file into the rrSubmitter. It will show the version in the lower left.
• Copy the contents of your HtoA... folder into this new folder
• If everything is setup right, then you find the kick executable in  [RR]\render_apps\renderer_exe\arnold\win_x64\HtoA-4.0.6.0\scripts\bin\kick

Modify Shared Executable folder for Arnold

You can simply change the location of the Shared Exe folder [RR]\render_apps\renderer_exe\arnold\[os] to something else.

Create a text file [RR]\render_apps\_config\A80__Arnold_StdA__inhouse.inc

Add a line:

ExeCopyFromDir = \\MyFileserver\Shaders\Arnold\

With this example path, the Arnold executable has to be in this path:  \\MyFileserver\Shaders\Arnold\Arnold-4.0.6.0\bin\kick

If you want to keep a setting for the OS, use for example

ExeCopyFromDir = \\MyFileserver\Shaders\Arnold\<rrOS>

rrOS is  replaced with "win", "lx" or "osx". (Note: without any "_x64")

License

If you want to add your license server to RR, then please edit [RR]\render_apps\_setenv\all\arnold__inhouse.rrEnv with baEnvFile_Editor (or a text editor).

If you are using a Solid Angle RLM  license: Uncomment the solidangle_LICENSE line and set your license server.

If you are using an Autodesk (clm) license: Uncomment the ADSKFLEX_LICENSE_FILE line and set your license server .

Test License

You can test if the license works and get some debug output in case it does not work with these commandlines.

Test RLM license server 

(Perhaps they might add Autodesk (CLM) to the test as well if many companies request it):
kick -licensecheck

Test RLM+CLM license server:

Linux/mac: kick -i /dev/null

Windows:   kick -i NUL

Look for the [clm] authorized   or   [rlm] authorized
or   rendering with watermarks because of failed authorization

If you are rendering with Maya, then you can edit the file RR\render_apps\_setenv\all\maya__inhouse.rrEnv to enable this license check.

Adlm.log

If you need more information about the issue, then you have to open the Adlm.log file:

• On Windows, look in %LOCALAPPDATA%\Autodesk\Logs
• On OSX, look in $TMPDIR
• On Linux, look in /var/tmp

Common VendorError values are

Autodesk License Registration

The Autodesk license might require Arnold to be registered in the Product Information file (aka the PIT file).
If this is not done, then CLM returns the error    Product Key Not Found (44) .

Clients using Arnold as a Shared Executable will need to run the product registration before their first use. 

Arnold version less 5.3:
To register Arnold on all clients using RR:

• Locate the file pitreg.exe in the Shared Exe folder, locations are [arnold]\pit\pitreg.exe, or [arnold]\license\pitreg.exe.
• Launch rrSubmitter, click Load Scene File, use the file browser to open the pitreg executable.
• Choose OnceEachClient as renderer, and assign the job to the Arnold clients.
• Submit the job.

Arnold version 5.3 (Autodesk products "2022"):

Windows: 

• Create a batch file with the commandline:
  "C:\Program Files (x86)\Common Files\Autodesk Shared\AdskLicensing\Current\helper\AdskLicensingInstHelper.exe" register --pk C0PN1 --pv 2022.0.0.F --lm NETWORK --cf "C:\Program Files\Autodesk\Arnold\maya2022-5.0.0.2\license\ArnoldConfig.pit"
• Change the path to the .pit file in the commandline according to the MtoA path that you use.
• Launch rrSubmitter, click Load Scene File, use the file browser to open the pitreg executable.
• Choose OnceEachClient as renderer, and assign the job to the Arnold clients.
• Submit the job.

Linux:
As you have to use sudo, it may not be possible to run this command via RR.
The commandline you have to use is:
sudo /opt/Autodesk/AdskLicensing/Current/helper/AdskLicensingInstHelper register --pk C0PL1 --pv 2020.0.0.F --lm NETWORK -cf /opt/Autodesk/arnold/maya2019-4.2.0/license/ArnoldConfig.pit

You could be able to use this commandline in a .sh shell script and pipe the password to sudo. 
$echo <password> | sudo -S <command>

Then follow the description for Windows to send the shell script to your farm.

Submission

Just like every other archive renderer type, you have to load one file of your .ass sequence into the rrSubmitter.

The rrSubmitter recognizes the frame range of your sequence and output name.

You can also start the rrSubmitter with the file as commandline parameter.

All Archive/Standalone renderer are based on a scene file per frame in Royal Render.

You can not export a complete animation into one file, you need one file per Frame.

name.#.ext

Infos

Tiled EXR

Arnold writes full-float tiled EXR by default.

You can enable/disable "Tiled" in your Arnold render settings.

Tiled EXR use a bit less memory as the image is not kept in RAM during the render.

The disadvantage of tiled images is that the output file is always valid to load.

RR can not detect if the image was finished or aborted/crashed.

No matter what you have set in your Arnold render settings, half-float scanline EXR are faster to load in compositing apps.

You can use the CropEXR job option to convert any .exr file them into  half-float scanline EXR files. 

(In addition CropEXR converts files into faster EXR 2.0 and reduces the image size by removing empty areas (crop region) as well)

Machines CPU

As of Arnold 4.2.13.0, the minimum requirement for CPUs is SSE4.2.

You can use baCPUInfo to test if the supports SSE4.2.

To check all your machines, please open the rrSubmitter and execute the menu item "Scripted Job; check for Arnold support" to get an Excel file with the information which machine supports Arnold.