Introduction

Arnold's command-line renderer is called kick. This reads an .ass and .usd file, renders the scene using Arnold, and outputs an image file. Kick can also be used to query Arnold nodes for their parameters and default values. It can also be used for scene debugging.

Kick is included in the plug-in downloads. After installation, you will find it in the bin subdirectory of the Arnold distribution.

Running Kick

To run kick, first, open a shell (terminal). Here's an example on Windows OS.

Kick always loads shaders and procedurals from the current directory, so don't run kick in a folder with lots of other DLLs/SOs/DYLIBs. Kick will try to load each DLL/SO/DYLIB, to check whether it contains shaders or procedurals.

$ set ARNOLD_BIN_PATH="C:\Program Files\Arnold-7.2.1.1\bin"
$ %ARNOLD_BIN_PATH%\kick
Arnold 7.2.1.1 [ec8a2acc] windows x86_64 clang-15.0.7 oiio-2.4.1 osl-1.12.9 vdb-7.1.1 adlsdk-7.4.2.47 clmhub-3.1.1.43 rlm-14.2.5 optix-6.6.0 2023/04/18 02:41:43
kick: No arguments. Try kick --help for a command summary 

Useful Commands

To try out the following commands download one of the files like cornell.ass from the example ass files page.

One of the most useful commands is "-h" or "--help". This will display a list of all the available options in kick:

kick -h 

Use the "-i" option to read an .ass file and render it:

kick -i path/to/cornell.ass 

Note that the "-i" option is not strictly necessary, kick automatically recognizes arguments ending in .ass, so this works too:

kick path/to/cornell.ass 

By default, a window will pop up displaying the image as it's being rendered. You can turn off the display window with the '-dw' option:

kick cornell.ass -dw 

If the geometry is colored pink, it could be because the path to the shaders may be required. This can be added using the "-l" flag:

kick cornell.ass -l /path/to/plugin/shaders/ 

Log information is sent to stdout. You can increase or decrease the log verbosity with the "-v " option (default verbosity is 1). The most verbose option is "-v 6":

kick cornell.ass -v 2 

Switch off the log output with "-v 0":

kick cornell.ass -v 0 

To save the rendered image in an output file use the "-o" flag:

kick cornell.ass -o cornell.exr 

Change the render display size with the "-r " option:

kick cornell.ass -r 1024 720 

Print the Arnold version number, or the entire version string:

kick -av
kick --version 

Print diagnostic information about the license servers and list installed licenses available and in use:

kick -licensecheck 

To override the antialiasing samples:

kick cornell.ass -as 3 

To override the diffuse GI samples:

kick cornell.ass -ds 3 

To disable the progressive refinement mode:

kick cornell.ass -dp  

For debugging purposes you can globally disable several features like textures, lights, and shaders, motion blur, subdivs, displacement or SSS:

kick cornell.ass -it 
kick cornell.ass -il 
kick cornell.ass -is
kick cornell.ass -imb -isd -idisp -isss 

You can install custom Arnold nodes by loading them from a dynamic library (.dll or .so) with:

kick cornell.ass -l path\to\plugin -l path\to\more\plugins 

You can also get a list of all the installed nodes (both built-in and dynamically-loaded) with:

kick -nodes
kick -l path\to\plugins -nodes 

You can inspect nodes with "-info":

kick -info polymesh 
kick -info options
kick -l path\to\plugins -info custom_plugin_node 

Or get more information about a given parameter:

kick -info polymesh.sidedness
kick -info options.bucket_scanning 

Override any parameter of any node using the "-set" command:

kick cornell.ass -set options.AA_samples 3 

Override any parameter of all nodes of a particular type:

kick cornell.ass -set curves.mode thick 

Get kick to abort the render if no valid license is found, rather than rendering with a watermark:

kick cornell.ass -set options.abort_on_license_fail true 

Override several parameters:

kick first.ass -set options.AA_samples 3 -set options.bucket_size 16 

Override several parameters:

kick first.ass -set options.AA_samples 3 -set options.bucket_size 16 

Specify which AOV to show in the kick display. You can display any of the built-in Arnold AOVs, such as N, cputime, direct, or specular, or any custom AOV defined in the ass file.

kick -aov direct

Interactive Mode

To render in interactive mode use the "-ipr q" option. This allows you to (very crudely) navigate the scene and switch to various debug shading modes such as flat/smooth normals, UVs, and wireframe

kick cornell.ass -ipr q 

• Navigate (pan/zoom) with the chosen interaction mode: "q" for Quake controls (WASD), and "m" for Maya controls (Alt + Mouse).
• Increase or decrease the image exposure with the "[" and "]" keys.
• Click in the render window and press lowercase "i" to ignore any existing shaders. You can restore the scene shaders by pressing uppercase "i"
• macOS and Linux: use the number keys (0,1,2,3,4,5,6,7,8,9) to switch between the various debug shading modes.