These changes are also true for PySide6.

1. OpenGL classes have been moved to a separate PyQt6.QtOpenGL namespace:

PyQt5:

from PyQt5.QtGui import (QOpenGLBuffer, QOpenGLShader, QOpenGLShaderProgram,
                        QOpenGLTexture)

PyQt6:

from PyQt6.QtOpenGL import (QOpenGLBuffer, QOpenGLShader, QOpenGLShaderProgram,
                           QOpenGLTexture)

2. The QOpenGLWidget class has been moved to the PyQt6.QtOpenGLWidgets namespace:

PyQt5:

from PyQt5.QtWidgets import QApplication, QOpenGLWidget

PyQt6:

from PyQt6.QtOpenGLWidgets import QOpenGLWidget

3. Changed enum for shader types:

PyQt5:

self.program.addShaderFromSourceCode(QOpenGLShader.Vertex, vertShaderSrc)
self.program.addShaderFromSourceCode(QOpenGLShader.Fragment, fragShaderSrc)

PyQt6:

self.program.addShaderFromSourceCode(QOpenGLShader.ShaderTypeBit.Vertex, vertShaderSrc)
self.program.addShaderFromSourceCode(QOpenGLShader.ShaderTypeBit.Fragment, fragShaderSrc)

4. Changed enum Target texture:

PyQt5:

self.texture = QOpenGLTexture(QOpenGLTexture.Target2D)

PyQt6:

self.texture = QOpenGLTexture(QOpenGLTexture.Target.Target2D)

5. Changed enum for setting texture filters:

PyQt5:

self.texture.setMinMagFilters(QOpenGLTexture.Linear, QOpenGLTexture.Linear)

PyQt6:

self.texture.setMinMagFilters(QOpenGLTexture.Filter.Linear, QOpenGLTexture.Filter.Linear)

6. Changed enum for WrapMode:

PyQt5:

self.texture.setWrapMode(QOpenGLTexture.ClampToEdge)

PyQt6:

self.texture.setWrapMode(QOpenGLTexture.WrapMode.ClampToEdge)

7. Changed enum to set application attributes:

PyQt5:

QApplication.setAttribute(Qt.AA_UseDesktopOpenGL)

PyQt6:

QApplication.setAttribute(Qt.ApplicationAttribute.AA_UseDesktopOpenGL)

A few basic non-graphical changes:

1. Changed enum for file open mode:

PyQt5:

file = QFile(path)
if not file.open(QIODevice.ReadOnly):
   print("Failed to open the file: " + path)

PyQt6:

file = QFile(path)
if not file.open(QIODevice.OpenModeFlag.ReadOnly):
   print("Failed to open the file: " + path)

2. The QApplication.exec_() method has been renamed to QApplication.exec()

PyQt5:

import sys
from PyQt5.QtWidgets import QApplication

app = QApplication(sys.argv)
sys.exit(app.exec_())

PyQt6:

import sys
from PyQt6.QtWidgets import QApplication

app = QApplication(sys.argv)
sys.exit(app.exec())

Bonus example:

Falling Collada Cube with Bullet Physics, OpenGL 3.3:

• PyQt6: https://github.com/8Observer8/falling-collada-cube-bullet-physics-opengl33-pyqt6​
• PySide6: https://github.com/8Observer8/falling-collada-cube-bullet-physics-opengl33-pyside6​

You should install these packages:

• pip install PyQt6 (or PySide6)
• pip install PyOpenGL
• pip install numpy
• pip install Panda3D (for Bullet Physics)