Loading meshes interactively with PyQt

[CorpsSansOrganes]

Hello everybody
I'm having difficultly acheiving a simple functionality when interacting with PyQt.
What I'm trying to achieve is a PyQt application which loads an .stl file, then renders it to screen. I would emphasize that in all the qt examples I've seen (in particular examples/other/qt_*) the object which will be rendered by the plotter is always known before the plotter is initialised. This is not the case with interactive applications, hence I'm a bit puzzled how to achieve this behaviour.

So far no matter what I did the plotter wouldn't update & show the recently acquired model. It seems like the plotter is initialised and then stuck.

Here's one example of my efforts:

class ThreeDPanel(QWidget):
   def __init__(self, model_manager: ModelManager, parent = None) -> None:
        super().__init__(parent)
        
        self.frame = QFrame()
        self.layout = QVBoxLayout()
        self.vtkwidget = QVTKRenderWindowInteractor(self.frame)

        self.setLayout(self.layout)
        self.layout.addWidget(self.vtkwidget)

        # Initialise the vedo Plotter which will handle 3D rendering
        self.plt = Plotter(qt_widget=self.vtkwidget, bg = 'white', interactive=False)
        self.plt.show()
        
        self.frame.setLayout(self.layout)
        self.show()

        # Subscribe to the model manager
        self._model_manager = model_manager
        model_manager.subscribe(self)

    def onClose(self):
        self.vtkwidget.close()

    def update(self) -> None:
       # This function is called by the model manager when a new 3D model is loaded.
        model = self._model_manager.get_current_model()
        if model is None:
            raise ValueError("3D panel was called to update, but no model is loaded")


        self.plt.clear()
        self.plt += model.to_vedo()
        self.plt.show()

Obviously I've verified that model.to_vedo() is a valid vedo.Mesh object, and that update() is actually called.

Would appriciate your help.
Thanks in advance.

[marcomusy]

You probably just need to reset the camera.. Check out this example:

import sys
import numpy as np
from PyQt5 import Qt
from vtk.qt.QVTKRenderWindowInteractor import QVTKRenderWindowInteractor
from vedo import Plotter, Sphere, Cone, printc

class MainWindow(Qt.QMainWindow):

    def __init__(self, parent=None):

        Qt.QMainWindow.__init__(self, parent)
        self.frame = Qt.QFrame()
        self.layout = Qt.QVBoxLayout()
        self.vtkWidget = QVTKRenderWindowInteractor(self.frame)

        # Create renderer and add the vedo objects and callbacks
        self.plt = Plotter(qt_widget=self.vtkWidget)
        self.id1 = self.plt.add_callback("mouse click", self.onMouseClick)
        self.id2 = self.plt.add_callback("key press",   self.onKeypress)
        self.plt += Cone().rotate_x(20)
        self.plt.show()                  # <--- show the vedo rendering

        # Set-up the rest of the Qt window
        button = Qt.QPushButton("Button adds a Sphere")
        button.setToolTip('This is an example button')
        button.clicked.connect(self.onClick)
        self.layout.addWidget(self.vtkWidget)
        self.layout.addWidget(button)
        self.frame.setLayout(self.layout)
        self.setCentralWidget(self.frame)
        self.show()                     # <--- show the Qt Window

    def onMouseClick(self, evt):
        printc("You have clicked your mouse button. Event info:\n", evt, c='y')

    def onKeypress(self, evt):
        printc("You have pressed key:", evt.keypress, c='b')

    @Qt.pyqtSlot()
    def onClick(self):
        printc("..calling onClick")
        sphere = Sphere(pos=np.random.rand(3)*10)
        sphere.color(np.random.rand(3))
        self.plt.add(sphere)
        self.plt.reset_camera().render()

    def onClose(self):
        printc("..calling onClose")
        self.vtkWidget.close()

if __name__ == "__main__":
    app = Qt.QApplication(sys.argv)
    window = MainWindow()
    app.aboutToQuit.connect(window.onClose)
    app.exec_()

[CorpsSansOrganes]

Reseting the camera fixed it. Thank you kindly, appriciate your help.