[MtoA] Getting the MtoA build ID


When you contact support or log bugs, it’s nice to provide the version number and build ID of the MtoA version that you’re using.

This information is displayed in the Arnold > About box.

mtoa_buildid

But the build id (circled in the screenshot) is kinda a pain to type out. Fortunately, you can get the build ID with the arnoldPlugins command:

arnoldPlugins -gbi;
// Result: 261bd4ca (master) //

You can get both the MtoA version and the MtoA build ID like this:

print( "MtoA " + `pluginInfo -v -q "mtoa.mll"` + " - " + `arnoldPlugins -gbi`);

In Python:

print( "MtoA {} - {}".format( cmds.pluginInfo( 'mtoa', query=True, version=True), cmds.arnoldPlugins(getBuildID=True) ) )
# MtoA 1.4.2.2 - 261bd4ca (master)

[MtoA] UnicodeEncodeError when rendering


UnicodeDecodeError

If you get this UnicodeEncodeError when you render

# Error: line 1: UnicodeEncodeError: file C:\Program Files\Autodesk\Maya2016\bin\python27.zip\encodings\utf_8.py line 16: ascii #

it’s probably because because the project folder has a special character in the name (for example, an accent mark like é).

If that’s not it, then we’d need more context (hint: everything else that is logged in the script history).

For a project name with a special character, you’ll see something like this in the script history:

file -f -save -options "v=0;";
// C:/maya/projects/New_Projéct/scenes/blank.mb // 
# Error: line 1: UnicodeEncodeError: file D:\Program Files\Autodesk\Maya2017\bin\python27.zip\encodings\utf_8.py line 16: ascii # 
# Error: line 1: UnicodeEncodeError: file D:\Program Files\Autodesk\Maya2017\bin\python27.zip\encodings\utf_8.py line 16: ascii #

 

 

[MtoA] What environment variables does MtoA use?


MtoA uses these environment variables:

  • ARNOLD_PLUGIN_PATH is for shaders.
    MtoA and kick use this environment variable. Arnold doesn’t (when you write Arnold code that loads an ASS file, Arnold doesn’t getenv ARNOLD_PLUGIN_PATH)
  • MTOA_TEMPLATES_PATH is for the Attribute Editor (AE) templates of Arnold shaders. For example, if you use the alShaders:
    set MTOA_TEMPLATES_PATH  C:\solidangle\alShaders\alShaders-win-1.0.0rc18-ai4.2.12.2\ae
  • MTOA_EXTENSIONS_PATH is for MtoA extensions like Yeti. By default, MTOA_EXTENSIONS_PATH points to the extensions folder in the MtoA installation.
  • MAYA_CUSTOM_TEMPLATE_PATH is for Node Editor templates for Arnold shaders. For example, if you use the alShaders:
    set MAYA_CUSTOM_TEMPLATE_PATH C:\solidangle\alShaders\alShaders-win-1.0.0rc18-ai4.2.12.2\aexml
  • My personal favorite, MTOA_STARTUP_LOG_VERBOSITY, sets the MtoA log verbosity during startup: 1 for Errors and Warnings, 2 for Errors, Warnings, and Info, and 3 for all. This can be handy for troubleshooting MtoA loading problems.
  • MTOA_LOG_PATH is the default location for Arnold log files.

These are not MtoA environment variables:

  • ARNOLD_PROCEDURAL_PATH is an HtoA environment variable. It’s not used by MtoA (or kick).
  • MTOA_PROCEDURAL_PATH doesn’t exist. No such environment variable is used or supported by MtoA.
  • [MtoA] Unable to dynamically load : mtoa.mll The specified module could not be found.


    I have another, more general, version of this post here. This one is for new Arnold users with Maya 2017.

    Here’s what to do if you get errors like this:

    // Error: file: C:/Program Files/Autodesk/Maya2017/scripts/startup/autoLoadPlugin.mel line 32: Unable to dynamically load : C:/solidangle/mtoadeploy/2017/plug-ins/mtoa.mll
    The specified module could not be found.
    //
    // Error: file: C:/Program Files/Autodesk/Maya2017/scripts/startup/autoLoadPlugin.mel line 32: The specified module could not be found.

    Check if your processor supports SSE4.1

    As of Arnold 4.2.16.2, the SSE requirement is now SSE4.1

    If this is the first time you’ve tried to use the Maya to Arnold (MtoA) plugin, then check whether your processor supports SSE4.1.

    Reinstall MtoA

    If MtoA used to load, but now it doesn’t, then something happened to the MtoA installation. I’ve seen several cases where DLLs were missing from the MtoA bin folder; most importantly, Arnold itself was missing (Arnold is ai.dll on Windows, or libai.so on Linux, or libai.dylib on OSX).

    If you make a backup copy of the MtoA install folder, we can investigate after you fix things by installing MtoA.

    Get a Process Monitor log

    If a clean install of MtoA doesn’t work (and the computer does support SSE4.1), then “The specified module could not be found.” usually means there’s a missing dependency. Dependency Walker is a decent, if aging, tool for checking out dependencies, but for leaving no stone unturned, I prefer Process Monitor.

    The MtoA plugin (mtoa.mll) depends on a handful of files only. Here’s the log of loaded DLLs for a working MtoA:

    process_monitor_mtoa

    Here’s a quick walkthrough (no audio) of how to get a Process Monitor log:

    [MtoA] The renderer ‘arnold’ used by this scene, is not currently available


    warning_renderer_not_currently_available

    // Warning: file: C:/Program Files/Autodesk/Maya2017/scripts/others/supportRenderers.mel line 64: The renderer "arnold" used by this scene, is not currently available. The "mayaSoftware" renderer will be used instead. //

    By itself, this warning doesn’t mean there’s a problem with MtoA or Arnold. The warning means that the MtoA plugin isn’t loaded, so all you have to do is load MtoA:

    1. Click Windows > Settings/Preferences > Plug-in Manager
    2. Scroll down until you see mtoa.mll
      plug-in_manager_mtoa
    3. Click the Loaded and Auto load check boxes.

    However, if you get a “Unable to dynamically load : ../mtoa.mll The specified module could not be found.” error, then that’s a different problem.

    [Arnold] [MtoA] How to check if your processor supports SSE4.1


    As of Arnold 4.2.16.2, the requirement is now “just” SSE4.1.

    This blog post is for Google search to find; I’ve already blogged about the SSE4.1 requirement elsewhere.

    If your processor does not support SSE4.1, the Arnold won’t run on your computer. MtoA will either fail to load, or you’ll get a crash whenever you try to render.

    To check whether an older machine supports SSE4.1, here’s a few suggestions:

    • Google your processor and “SSE”
      cpu-world is pretty reliable, but I have seen one or two cases where the info was wrong, and SSE4.1 wasn’t really supported by a processor.
    • Windows: Download and run coreinfo -f
    • OSX: Run sysctl -a | grep machdep.cpu.features
    • Linux: Check /proc/cpuinfo

    A note about coreinfo:

    • If you see an asterisk (*), then SSE4.1 is supported.
      SSE4.1          *       Supports Streaming SIMD Extensions 4.1
    • If you see a dash (-), then SSE4.1 is not supported.
      SSE4.1          -       Supports Streaming SIMD Extensions 4.1

    [MtoA] The curse of pymel.log


    PyMEL is great. But…if pymel.log can’t be accessed, any plugin that uses PyMEL will fail to load.

    And MtoA uses PyMEL, so every now and again I see a case where MtoA doesn’t load, and you get something like this in the script history:

    import arnold
    // Successfully imported python module 'arnold'
    import mtoa
    // Successfully imported python module 'mtoa'
    import mtoa.cmds.registerArnoldRenderer;mtoa.cmds.registerArnoldRenderer.registerArnoldRenderer()
    # Error: line 1: IOError: file C:\Program Files\Autodesk\Maya2016\bin\python27.zip\logging\__init__.py line 926: 13 #
    // Error: Failed to register renderer 'arnold' //
    // Error: line 1: initializePlugin function failed (mtoa) //

    The important bit is this error:

    # Error: line 1: IOError: file C:\Program Files\Autodesk\Maya2016\bin\python27.zip\logging\__init__.py

    That error means that PyMELcannot create a log file in your user folder.

    By default, the PyMEL log file is created in your Documents folder. For example, if your Windows user account name is Stephen, then this would be the log file:

    C:\Users\Stephen\Documents\pymel.log

    You need to check the permissions on that log file, or delete it so that PyMel can create a new log file.

    Note that the pymel.log file may be a hidden file.