WARNING | unable to load dynamic library .\ai_renderview.dll: The specified module could not be found.

kick checks the current working directory for plugins (shaders and procedurals). That means kick tries to load all .dll/.so/.dylib files in the current directory.

So if you do this:

cd C:\solidangle\mtoadeploy\2017\bin
kick -nodes

Then you’ll get a warning like this (plus a pop-up System Error dialog that says “Qt5Core.dll is missing from your computer”).

loading plugins from .
WARNING | unable to load dynamic library .\ai_renderview.dll: The specified module could not be found.

On OSX, the warning would  say ./libai_renderview.so, and on Linux, ./libai.so

Notice the “loading plugins from .” The single period, or dot, represents the current directory.

The solution? Don’t run kick in the MtoA bin folder. Don’t run kick in an any folder where there are non-plugin libraries.


[Arnold] [kick] Enabling tiled EXRs

Suppose you have a load of ASS files that were exported with the Tiled option disabled. How could you re-enable the Tiled option without re-exporting the ASS files?

With the kick -set flag, that’s how:

kick -set display_exr.tiled on

That will set the tiled parameter for all EXR driver nodes in the ASS file.

If you want to set the flag for a specific driver node, you need to know the driver node name.

kick -set defaultArnoldDriver@driver_exr.RGBA.tiled on

That sets tiled for the driver_exr node named defaultArnoldDriver@driver_exr.RGBA.

Portable ASS files with relative paths and the Texture Search Path

You can make your ASS files portable across different platforms by using relative paths and the texture search path. For example, if all textures are specified by relative paths like “textures/noicon.tx”, then you just have to set options.texture_searchpath to specify the location of the textures folder.

For example

kick -set options.texture_searchpath //server/project/ -dp -dw example.ass

Or if the texture search path is set to an environment variable

export ARNOLD_TEXTURE_PATH=//server/project
./kick example.ass

To use relative paths for texture file names in nodes like MayaFile, aiImage, aiPhotometricLight, and aiSkydomeLight, you just need to do the following:

  • Put a relative path in the file name box (for example, in Photometry File box of an aiPhotometricLight node, or the Image Name box of an aiImage node)
  • Set the Texture Search Path (Render Settings > System > Search Paths)
  • Clear the Absolute Texture Paths check box

You can put multiple locations, using either : or ; to separate the paths (Arnold supports both separators on all platforms: OSX, Linux, and Windows)

You can use environment variables by putting the environment variable name in square brackets. For example:


Forward slashes work on all platforms.

MtoA appends the current project’s sourceimages folder to the texture search path.

Why can’t I use kick -set options.shader_searchpath ?

You may wonder: why can’t I use kick -set options.shader_searchpath to tell Arnold where to find shaders?

Well, it’s because kick loads the ASS file first, then applies the kick -set parameter overrides. And also, Arnold when loads an ASS file, Arnold automatically loads shaders from the shader_searchpath as soon as Arnold loads the options node.

Here’s the sequence of events:

  1. kick loads all plugins specified by -l or by ARNOLD_PLUGIN_PATH before it loads the ASS file
  2. kick loads the ASS file. When Arnold loads the options node, Arnold automatically loads all plugins specified by options.shader_searchpath.That’s why the options node is at the top of an ASS file: so Arnold can load any required shaders before loading the shader nodes. It you move the options to bottom of the ASS file, the shader nodes in the ASS file won’t be loaded.
  3. Finally, after all the nodes are loaded, the -set parameter overrides are applied. At this point, it’s too late for any shaders from the -set options.shader_searchpath loacation. The corresponding nodes were already discarded during the loading of the ASS file.


WARNING mtoa_shading_groups: unresolved reference

Any time you see “node … is not installed” and “unresolved reference” warnings when you try to kick an ASS file exported from Maya, the problem is missing MtoA shaders.

00:00:00 18MB WARNING | [ass] line 259: node "MayaFile" is not installed
00:00:00 18MB WARNING | [ass] line 288: node "MayaShadingEngine" is not installed

00:00:03 23MB WARNING | [ass] line 238: pSphereShape1.mtoa_shading_groups: unresolved reference to 'aiStandard2SG'
00:00:03 23MB WARNING | [ass] line 137: aiSkyDomeLightShape1.color: unresolved reference to 'file1'
00:00:03 23MB WARNING | [ass] line 188: pPlaneShape1.shader: unresolved reference to 'aiStandard1SG'
00:00:03 23MB WARNING | [ass] line 197: pPlaneShape1.mtoa_shading_groups: unresolved reference to 'aiStandard1SG'
00:00:03 23MB WARNING | [ass] line 229: pSphereShape1.shader: unresolved reference to 'aiStandard2SG'

When you render with kick, you need to specify the location of the MtoA shaders. You can do this several ways:

  • Set the ARNOLD_PLUGIN_PATH environment variable. For example:
    export ARNOLD_PLUGIN_PATH=/home/render/solidangle/mtoa/2016/shaders
    set ARNOLD_PLUGIN_PATH=C:\solidangle\mtoadeploy\2016\shaders
  • Use the kick -l flag to specify the MtoA shader location.
  • In Maya, set the Shader Search Path in the Arnold Render Settings, then export the ASS file.

[Arnold] [kick] Changing output paths for AOVs

The -o flag changes the output path for the beauty AOV only. For other AOVs, kick still uses the output paths specified in the ASS file (the AOV output paths are specified by the filename parameter of the driver nodes in an ASS file).

 name defaultArnoldDriver@driver_exr.RGBA.direct_diffuse
 filename "C:/Users/StephenBlair/Documents/maya/projects/Support/images/direct_diffuse/Natural_Museum.exr"
 compression "zip"
 half_precision off
 tiled off
 preserve_layer_name off
 autocrop off
 append off

It is possible, however, to use kick -set to change the output path and file name of specific AOVs, but you’d have to know the AOV names in advance. For example:

kick -set defaultArnoldDriver@driver_exr.RGBA.direct_diffuse.filename "C:/temp/direct_diffuse.exr" -i example.ass

[kick] [ass] reading from stdin

Some customers have reported a problem using a render manager (Muster, Tractor, Deadline) to render jobs with kick, typically via a wrapper script. The problem is that kick tries to read from STDIN instead of loading the specified ASS file. In the log, you’d see this:

00:00:00     0MB         | [ass] reading from stdin ...

A workaround is to add the -nstdin flag (Ignore input from stdin) to the kick command line.