If you’re like me, you like to always be using the latest version of an Autodesk product. The 2014 series has just been released and it is always quite a bit of work to convert you’re existing toolset up to the latest build.

In the case of Maya 2014, there are more than just a few issues, such as:

Python 2.6.3 -> Python 2.7.3
PyQt to PySide
PyMel 1.0.4 -> PyMel 1.0.5
Perforce module

Then there are always third-party compiled plug-ins to worry about. Any smart team will try to keep these to a minimum.

So the first big issue is the Python version upgrade. This should not be too big and on the surface it makes some sense to move up to the latest (last!) and greatest of the Python 2.x series. I’m pretty sure 2.7 will be the last of the supported 2.x series as everybody is supposed to move up to 3.x as soon as possible. My theory is that there will be some critical mass hit where most have updated to 3.x in their pipeline and then practically everybody else will migrate over in a very short period of time. I have not personally seen the roadmap for when this will happen to Maya (and probably non-coincidentally MotionBuilder 2014 which is using Python 2.7.3 now as well) but I suspect they’ll upgrade to a 3.x soon.

P4Python

The first heavily used third-party python module that I needed to upgrade was Perforce, which happened to be one of the most problematic. Unfortunately, the build of P4Python from the Perforce website does not import into Maya’s 2.7.3 python. According to this chart:

For detailed compatibility, please check the following table:

Python Release | P4Python Release
======================================
2.3 or earlier | not supported
2.4 | 2008.2 (unsupported)
2.5 | 2007.3 up to 2009.2 (unsupported)
2.6 | 2009.1 or later
2.7 | 2010.1 or later
3.0 | 2010.1 or later (unsupported)
3.1 | 2010.2 or later (unsupported)
3.2 | 2011.1

any of the latest versions (> 2010.1) of P4Python should work. However none of them do. I’ve tried all of them.

It seems that you must make a special custom build with “the version of Visual Studio that was used to build Maya” which is supposed to be VS2010. (Building P4Python and PyQt for Maya 2014). I had a hard time getting this to work, but with some help from one of my buddies I configured a simple build .bat file for you. You can get it here: perforce_build_x64_maya.bat or if you just want the results, go get the builds here: P4Python compiled for ADSK 2014 download (64-bit, of course) These should import fine into both Maya and MotionBuilder 2014 64-bit.

PySide

Autodesk now ships pre-compiled builds of PySide which is a replacement wrapper for the QT UI libraries that work so well and are so robust and beautiful in some of the latest Autodesk products. This is a huge relief as the licensing around the PyQt wrappers were tricky and some companies were reluctant to adopt and also you were supposed to build them yourself, though there was always a version floating around the interwebs you could find, if you looked hard enough. The coolest thing about PySide is that it is Open Source.

There are quite a lot of little tricks to getting Qt UIs embedded inside of Maya and get them talking together. For the most part, these have been thoroughly explored and there are solutions or workarounds for most common use cases inside of Maya. Nathan Horne is one of the pioneers in this area and has shared a ton of useful info: Nathan’s Mega-post and some others

After reading through that ton of info and if you’ve implemented Qt into Maya, you’ll know that the wrapinstance() function is a key component to getting it all going. Luckily Nathan wrote an equivalent for PySide: here

If you’re like me, you like loading Qt .ui files directly into Maya instead of compiling them into python via the pyuic.exe process. You’ll need to use the loadUiType() function to do this. This function needs to be modified slightly to accomodate PySide. Here ya go!: PySide loadUiType.py

import pysideuic
import xml.etree.ElementTree as xml
from cStringIO import StringIO
#import QtGui

def loadUiType(uiFile):
		"""
		Pyside lacks the "loadUiType" command, so we have to convert the ui file to py code in-memory first
		and then execute it in a special frame to retrieve the form_class.
		"""
		parsed = xml.parse(uiFile)
		widget_class = parsed.find('widget').get('class')
		form_class = parsed.find('class').text

		with open(uiFile, 'r') as f:
			o = StringIO()
			frame = {}

			pysideuic.compileUi(f, o, indent=0)
			pyc = compile(o.getvalue(), '', 'exec')
			exec pyc in frame

			#Fetch the base_class and form class based on their type in the xml from designer
			form_class = frame['Ui_%s'%form_class]
#			base_class = eval('QtGui.%s'%widget_class)
			base_class = eval('PySide.QtGui.%s'%widget_class)
		return form_class, base_class

You’ll notice QtGui replaced with PySide.QtGui.

I happen to use a lot of the decorator tricks for signal/slot connections and there are some marked differences in the way PyQt does these compared to PySide. Here’s two pages with some helpful examples:
Signals and Slots
Tutorial
Trickier examples

I also happen to find the Documentation for PySide very clear and easy to use. Here’s one of my favorite sites: PySide – Python for Qt

Here’s some other nice pages with PyQt to PySide conversion help: PySide and PyQt

and a supposed auto-converter?: PySider

PyMel

PyMel version has been iterated as well and with it comes some improvements, I’m sure. However, there are some minor issues introduced as well. The first couple I’ve found are related to the area of Virtual Class creation discussed here. It seems the factories.py module has a minor bug in it that you need to hack. I’ve submitted the bug request at the pymel google code repo where the project is maintained, but until that gets fixed, if you are using the pymel.all.factories.registerVirtualClass() method you need to hack ‘validSpecialAttrs’ variable in PyMel’s factories.py and add ‘__apicls__’ to the declaration.

To be continued, probably

Those are the major hurdles I’ve had to overcome so far in upgrading. If you have any questions or find any other obvious areas that need attention when you upgrade your toolset to Autodesk 2014, let me know and I’ll try to keep a running list here. Good luck.