Custom Engine - loading Apps

Pipeline Integrations
1

Hi there,

i’m trying to write a very simple Custom Engine (tk-deadline) just to be able to access some SG Apps in our Render Farm Manager (Deadline). Deadline includes Python and PyQt5, so i thought it wouldn’t be such a big deal :wink:

I defined properties like:

@property
def has_ui(self):
    return True

@property
def has_qt5(self):
    return True

I added the new Engine to engine_locations.yml and created a settings file (tk-deadline.yml) which looks like:

includes:
- ../app_locations.yml
- ../engine_locations.yml
- ./tk-multi-daily.yml

settings.tk-deadline.shot_step:
  apps:
    tk-multi-daily: '@settings.tk-multi-daily.deadline'
  location: '@engines.tk-deadline.location'

Last step to load the Engine was to define Engine in the environment file (i.e. shot_step.yml):

includes:
......
- ./includes/settings/tk-shotgun.yml

engines:
  ...........
  tk-deadline: "@settings.tk-deadline.shot_step"

And i added “tk-deadline” to the list of supported Engines of the belonging SG Apps (info.yml).

In the end everything seems to get loaded except QT. The log files shows me the following error:

AttributeError: 'NoneType' object has no attribute 'QWidget'

which comes from the app (tk-multi-daily):

from tank.platform.qt import QtCore, QtGui
class GeneralTab(QtGui.QWidget):
    def __init__(self, parent=None):
        super(GeneralTab, self).__init__()

There is no ImportError and the Engine gets also started without Errors in the right Context.
I tried pre import “from tank.platform.qt import QtCore, QtGui” in the function pre_app_init(), but it does not change anything.

Has anybody an idea why “QtGui” could be “None” and what i have change to load PyQt properly?

Many thanks
David

3 Likes
2

Hmm, for Qt 5, try using QWidgets instead

from tank.platform.qt5 import QtCore, QtWidgets
class GeneralTab(QtWidgets.QWidget):
    def __init__(self, parent=None):
        super(GeneralTab, self).__init__()

As far as I’m aware, there isn’t much testing done for PyQt5 officially since most DCC apps are using PySide*. Katana is using PyQt* and in case you run into any PyQt* errors with any apps, check the app’s GitHub Pull Request page to see if there are any fixes for it

3

Apart from the namespace import issue mentioned you might find that tk-core won’t support a PyQt5 based engine properly. I have a PR for tk-core to support PyQt5 that can be used. It’s been tested on a custom tk-katana engine.

2 Likes
4

You could also try bundle those pyqt5_patcher.py and qt_importer.py changes in your own engine too if you don’t feel like forking a separate copy of tk-core

See also:

1 Like
5

Thanks @j0yu and @Halil ! I will give it a try :nerd_face: