why bqt

Custom UI for Python tools in games & VFX often use QT.
Maya, Max & Substance support Qt natively, but Blender doesn't. This is where BQT can help.

Bqt takes care of the heavy lifting, so you can focus on your qt tools.

• manage focus of widgets, letting you parent widgets to blender
• manage QApplication setup for you (the qt eventloop)
• prevent widgets from being garbage collected
• auto style your widgets to match Blender's UI

More info

from PySide2.QtWidgets import QWidget
QWidget().show()

When attempting to run a simple widget, it will crash because we don't have a QApplication.
Manually _exec a new QApplication freezes Blender untill you close your custom window. (first time only)

• bqt manages the QApplication for you, use QApplication.instance() to access it if needed.

• The widget briefly shows & dissapears because it's garbage collected.
• The widget dissapears behind Blender when you click on Blender

To prevent these issues, parent the widget to ]QAppliciation.instance().blender_widget (blender_widget is created by bqt on startup).