Tutorial: Making Maya 2015 plugins with Visual Studio.

My Scripting and Dynamics coursework involves working with the Maya C++ API, which has meant puzzling through the not-so-well-documented process of setting up Visual Studio projects which will build plugins Maya can load and call commands from. Here’s a step-by-step guide:

The Simplest Possible Plugin

Open Visual Studio. I’m using 2013, but this stuff ought to be transferable to other versions. With a bit of tweaking, anyway.
Make a new empty project. Give it a nice, descriptive name.
Add a new C++ source file called ‘hello_maya.cpp’
Copy and paste this code into it:


#include <maya\MSimple.h>
#include <maya\MGlobal.h>

DeclareSimpleCommand(HelloMaya, "Rachel Crawford", "1.0";);

MStatus HelloMaya::doIt(const MArgList& args) {
    MGlobal::displayInfo("Hello Maya!");
    return MS::kSuccess;
}

(I’ll explain what it does in a minute.)

Open the project’s properties.
Open Configuration Manager, and set the active solution platform to x64.
Under General:
- Set Target Extension to .mll
- Set Configuration Type to ‘Dynamic Library (.dll)’
Under C/C++:
- General:
  - In Additional Include Directories, put Path\to\Maya2015\include.
- Preprocessor:
  - In Preprocessor Definitions, add WIN32; NDEBUG; _DEBUG; _WINDOWS; NT_PLUGIN; REQUIRE_IOSTREAM; _USRDLL; MAYAPLUGIN1_EXPORTS;
- Code Generation:
  - Set Runtime Library to ‘Multi-threaded Debug DLL’
Under Linker:
- General:
  - Set Output File to $(OutDir)$(ProjectName).mll
  - Additional Library Directories: Path\to\Maya2015\lib.
- Input:
  - Additional Dependencies: Foundation.lib; OpenMaya.lib; OpenMayaUI.lib; OpenMayaAnim.lib; OpenMayaFX.lib; OpenMayaRender.lib; Image.lib; opengl32.lib;
- Command Line:
  - Additional Options: /export:initializePlugin /export:uninitializePlugin

The hard part is over. Build your project and you should get a file called ‘$your_plugin_name.mll’.

Now open Maya 2015. Navigate to Window -> Settings/Preferences -> Plug-in Manager. Scroll down the window to the bottom. Click ‘Browse’ and navigate to and select your .mll file. Provided it loads correctly, it should appear in the Plug-in Manager window beneath “Other Registered Plugins”. Check the ‘Loaded’ checkbox next to it.

Now you should be able to just type “HelloMaya” into a MEL script or “maya.cmds.HelloMaya()” into a Python script and Maya will print “// Hello Maya! //” to the console.

So what does the code do? In Maya plugins, you create new commands as classes which inherit from the MPxCommand class. You declare the class, you give it a creator method and a doIt method, then you write two functions, initializePlugin and uninitializePlugin, in which you register and unregister the new class with the Maya API. That’s a lot of busywork for a simple plugin which only adds a single custom command, though, which is why the DeclareSimpleCommand macro exists. It does everything except define the command’s doIt method, which is left up to you. The flip-side is that it locks you in to having only one custom command in your plugin.

When you’re ready to move on, unload the plugin by un-checking ‘Load’ in the Plugin Manager. While the .mll is being used by Maya, we won’t be able to overwrite it with new versions of the plugin built by Visual Studio.

The Expanded Simplest Possible Plugin

Now we’ll expand on our work so far to create a good starting point for a plugin project.

Scrap the current version of hello_maya.cpp and bring in 3 new files: plugin_main.cpp, hello_maya.h, hello_maya.cpp. You can get the source code for these here. This time, instead of using the DeclareSimpleCommand macro we go the long way around and do all the things it does by hand.

If it builds and works, you can take a look at the code yourself and see how a budding plugin developer goes about making new commands to use in Maya.

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