NotImplementedError: pure virtual method 'QAbstractCameraController.moveCamera' not implemented.

[manuelo]

Hi all,

I'm using PySide6 on Python 3.11 on Mac and Linux. I'm trying to create a Trackball to Qt3D in Python based on this https://github.com/cjmdaixi/Qt3DTrackball. So I'm creating the TrackballCameraController inheriting from QAbstractCameraController.moveCamera. Here a simple sample:

import sys
from typing import Optional

from PySide6.Qt3DCore import Qt3DCore
from PySide6.Qt3DExtras import Qt3DExtras
from PySide6.Qt3DInput import Qt3DInput
from PySide6.Qt3DRender import Qt3DRender
from PySide6.QtCore import QObject, QPoint, QSize, QUrl
from PySide6.QtGui import QColor, QGuiApplication, QVector3D, qRgb
from PySide6.QtWidgets import QApplication


class TrackballCameraController(Qt3DExtras.QAbstractCameraController):
    def __init__(self, parent: Optional[Qt3DCore.QNode]=None):
        super().__init__(parent)

    def moveCamera(self, state: Qt3DExtras.QAbstractCameraController.InputState, dt: float):
        print("moveCamera")


def create_sphere(parent: Qt3DCore.QEntity) -> Qt3DCore.QEntity:
    # Create sphere mesh
    sphere_mesh = Qt3DExtras.QSphereMesh(parent)
    sphere_mesh.setRadius(3.0)

    # Create sphere material
    sphere_material = Qt3DExtras.QPhongMaterial(parent)
    # sphere_material.setDiffuse(QColor(255, 0, 0))
    #
    sphere_transform = Qt3DCore.QTransform(parent)
    # sphere_transform.setTranslation(QVector3D(-3, -3, -3))

    # Create sphere entity
    sphere_entity = Qt3DCore.QEntity(parent)
    sphere_entity.addComponent(sphere_mesh)
    sphere_entity.addComponent(sphere_transform)
    sphere_entity.addComponent(sphere_material)

    return sphere_entity


if __name__ == "__main__":
    # Create application
    app = QGuiApplication(sys.argv)

    # Create window
    window = Qt3DExtras.Qt3DWindow()
    window.setTitle("Sphere Example")

    # Create root entity
    root_entity = Qt3DCore.QEntity()

    # Create sphere entity
    sphere_entity = create_sphere(root_entity)

    print(sphere_entity.components())

    camera = window.camera()
    camera.setPosition(QVector3D(0.0, 0.0, 40.0))
    camera.setViewCenter(QVector3D(0.0, 0.0, 0.0))
    camera.lens().setPerspectiveProjection(45.0, 16.0 / 9.0, 0.1, 1000)

    camera_controller = TrackballCameraController(root_entity)
    camera_controller.setCamera(camera)

    # Set root entity as the root of the scene
    window.setRootEntity(root_entity)
    window.defaultFrameGraph().setClearColor(QColor(0, 0, 255))
    # Show window
    window.show()

    # Run application
    sys.exit(app.exec())

But I'm getting this error:

Qt3D.Renderer.RHI.Backend: Initializing RHI with Metal backend
Traceback (most recent call last):
  File "/Users/thiago/Sources/qt3d_experiments/draw_sphere.py", line 73, in <module>
    sys.exit(app.exec())
             ^^^^^^^^^^
NotImplementedError: pure virtual method 'QAbstractCameraController.moveCamera' not implemented.

But I implemented moveCamera in my child class... Is it correct to inherit from QAbstractCameraController? Do I need to do more things to inherit from QAbstractCameraController?

[SGaist]

@manuelo It's a now know issue, see PYSIDE-2255.

[SGaist]

Hi and welcome to devnet,

Which version of PySide6 are you using ?

[manuelo]

Hi @SGaist and thanks!

I'm using PySide6 6.4.2 installed from Pypi. If I run the sample code I posted in Linux the sphere doesn't show and when I close the window the process doesn't stop, I have to kill it. If I comment the part that creates the TrackballCameraController this problem doesn't happen.

[manuelo]

Tested on Windows 11, Python 3.11, PySide6 6.4.2 and this error happens:

Qt3D.Renderer.RHI.Backend: Initializing RHI with DirectX backend
Qt3D.Renderer.RHI.Backend: Can't create pipeline, incomplete SwapChain and no default Render Target

If I comment the part that creates the TrackballCameraController this problem doesn't happen.

[SGaist]

@manuelo It's a now know issue, see PYSIDE-2255.

[manuelo]

Fixed on the 6.4.3.