openMaya contexts

Coding
1

hey im trying to figure out how to create contexts in maya via the python api

this is what i got this thus far.


import maya.OpenMaya as om
import maya.OpenMayaMPx as mpx
import sys


kPluginCtxName = 'myContext'
kPluginCmdName = 'myContextCmd'


class context(mpx.MPxContext):
    def __init__(self):
        mpx.MPxCommand.__init__(self)

    def doPress(self, event):
        sys.stderr.write('It works I hope!!!!!')


class contextCommand(mpx.MPxContextCommand):
    def __init__(self):
        mpx.MPxContextCommand.__init__(self)

    def makeObj(self):
        return mpx.asMPxPtr(context())

    @classmethod
    def creator(cls):
        return mpx.asMPxPtr(cls())


def initializePlugin(mobject):
    mplugin = mpx.MFnPlugin(mobject, "Passerby", "1.0", "Any")
    try:
        mplugin.registerContextCommand(kPluginCtxName, contextCommand.creator)
    except:
        sys.stderr.write("Failed to register context command: %s
" % kPluginCtxName)
        raise


# Uninitialize the script plug-in
def uninitializePlugin(mobject):
    mplugin = mpx.MFnPlugin(mobject)
    try:
        mplugin.deregisterContextCommand(kPluginCtxName, kPluginCmdName)
    except:
        sys.stderr.write("Failed to deregister context command: %s
" % kPluginCtxName)
        raise

the plugin loads without errors, but the problem is once i call maya.cmds.myContext() i get this error.

# Error: TypeError: file <string> line 2: Swig director type mismatch in output value of type 'MPxContext *' #
2

my bad it was just a type on line 12 was calling the wrong init()

3

Hey Passerby,

Sorry to resurrect an old thread, but I am trying to create my own context and you seem to have had luck with it.

My goal is to create a python context that enables me to click and drag in a viewport to edit a voxel terrain, so ideally I need to click and drag across multiple meshes and “collect” the faces that are being touched. I haven’t really jumped into Python that much before so I am using this as a good learning lesson.

I am porting my Unity voxel terrain editor to Maya:

I tried testing your code above. I modified it so it loads the plugin correctly, and I can call maya.cmds.myContext() successfully, but when I click in the viewport I was hoping that ‘It works I hope!!!’ would print but it does not.

Any advice you could offer to point me in the right direction would be much appreciated! Thanks!

4

Ah finally got it to work. Took forever but I found out this context setup only works in Legacy Default Viewport (not viewport 2.0). Switching it to Legacy and all a sudden all my mouse events are firing! Yay!