# OpenGL State Errors with QVTKOpenGLWidget

**URL:** https://discourse.vtk.org/t/opengl-state-errors-with-qvtkopenglwidget/8365
**Category:** Support
**Created:** [April 25, 2022, 2:25am UTC](https://discourse.vtk.org/t/opengl-state-errors-with-qvtkopenglwidget/8365 "2022-04-25T02:25:23Z")
**Posts on this page:** 1
**Page:** 1

<div class="post-metadata">

### Author: ![Panda12197](https://discourse.vtk.org/letter_avatar_proxy/v4/letter/p/e480ec/32.png) [@Panda12197](https://discourse.vtk.org/u/Panda12197)
#### Post date: [April 25, 2022, 2:25am UTC](https://discourse.vtk.org/t/opengl-state-errors-with-qvtkopenglwidget/8365/1 "2022-04-25T02:25:23Z")

</div>

Hello Guys,

I have a problem in visualizing point cloud with **QVTKOpenGLWidget**. I promoted the QWidget to QVTKOpenGLWidget and load point cloud data to the Widget. As soon as the MainWindow is appeared, the following error are shown;

```auto
Generic Warning: In /home/Software/vtk-v8.2.0/Rendering/OpenGL2/vtkOpenGLState.cxx, line 401
Error glClearDepth1 OpenGL errors detected
  0 : (1282) Invalid operation

 with stack trace of
0x7fb2c7f36c : vtksys::SystemInformationImplementation::GetProgramStack[abi:cxx11](int, int) [(libvtksys-8.2.so.1) ???:-1]
0x7fb2c79e44 : vtksys::SystemInformation::GetProgramStack[abi:cxx11](int, int) [(libvtksys-8.2.so.1) ???:-1]
0x7fb43741ec : ??? [(???) ???:-1]
0x7fb4374a0c : vtkOpenGLState::vtkglClearDepth(double) [(libvtkRenderingOpenGL2-8.2.so.1) ???:-1]
0x7fb435d5dc : vtkOpenGLRenderer::Clear() [(libvtkRenderingOpenGL2-8.2.so.1) ???:-1]
0x7fb42a3850 : vtkOpenGLCamera::Render(vtkRenderer*) [(libvtkRenderingOpenGL2-8.2.so.1) ???:-1]
0x7fb482fbc0 : vtkRenderer::UpdateCamera() [(libvtkRenderingCore-8.2.so.1) ???:-1]
0x7fb435b4f0 : vtkOpenGLRenderer::DeviceRender() [(libvtkRenderingOpenGL2-8.2.so.1) ???:-1]
0x7fb482f540 : vtkRenderer::Render() [(libvtkRenderingCore-8.2.so.1) ???:-1]
0x7fb482cc58 : vtkRendererCollection::Render() [(libvtkRenderingCore-8.2.so.1) ???:-1]
0x7fb484a704 : vtkRenderWindow::DoStereoRender() [(libvtkRenderingCore-8.2.so.1) ???:-1]
0x7fb484a4fc : vtkRenderWindow::Render() [(libvtkRenderingCore-8.2.so.1) ???:-1]
0x7fb4357390 : vtkOpenGLRenderWindow::Render() [(libvtkRenderingOpenGL2-8.2.so.1) ???:-1]
0x7fb428e014 : vtkGenericOpenGLRenderWindow::Render() [(libvtkRenderingOpenGL2-8.2.so.1) ???:-1]
0x7fb48579a0 : vtkRenderWindowInteractor::Render() [(libvtkRenderingCore-8.2.so.1) ???:-1]
0x7fb4a6ee28 : QVTKOpenGLWindow::paintGL() [(libvtkGUISupportQt-8.2.so.1) ???:-1]
0x7fb25f0744 : QPaintDeviceWindow::exposeEvent(QExposeEvent*) [(libQt5Gui.so.5) ???:-1]

```

But PCD file can be loaded successfully, and point cloud is shown but the program is crashed after mouse click in the widget for about five times. The following errors is show for all mouse event (mouse move, mouse press, mouse release and wheel movement) in the widget;

```auto
Generic Warning: In /home/Software/vtk-v8.2.0/Rendering/OpenGL2/vtkOpenGLState.cxx, line 401
Error glClearDepth1 OpenGL errors detected
  0 : (1282) Invalid operation

 with stack trace of
0x7f8f8e436c : vtksys::SystemInformationImplementation::GetProgramStack[abi:cxx11](int, int) [(libvtksys-8.2.so.1) ???:-1]
0x7f8f8dee44 : vtksys::SystemInformation::GetProgramStack[abi:cxx11](int, int) [(libvtksys-8.2.so.1) ???:-1]
0x7f90fd91ec : ??? [(???) ???:-1]
0x7f90fd9a0c : vtkOpenGLState::vtkglClearDepth(double) [(libvtkRenderingOpenGL2-8.2.so.1) ???:-1]
0x7f90fc25dc : vtkOpenGLRenderer::Clear() [(libvtkRenderingOpenGL2-8.2.so.1) ???:-1]
0x7f90f08850 : vtkOpenGLCamera::Render(vtkRenderer*) [(libvtkRenderingOpenGL2-8.2.so.1) ???:-1]
0x7f91494bc0 : vtkRenderer::UpdateCamera() [(libvtkRenderingCore-8.2.so.1) ???:-1]
0x7f90fc04f0 : vtkOpenGLRenderer::DeviceRender() [(libvtkRenderingOpenGL2-8.2.so.1) ???:-1]
0x7f91494540 : vtkRenderer::Render() [(libvtkRenderingCore-8.2.so.1) ???:-1]
0x7f91491c58 : vtkRendererCollection::Render() [(libvtkRenderingCore-8.2.so.1) ???:-1]
0x7f914af704 : vtkRenderWindow::DoStereoRender() [(libvtkRenderingCore-8.2.so.1) ???:-1]
0x7f914af4fc : vtkRenderWindow::Render() [(libvtkRenderingCore-8.2.so.1) ???:-1]
0x7f90fbc390 : vtkOpenGLRenderWindow::Render() [(libvtkRenderingOpenGL2-8.2.so.1) ???:-1]
0x7f90ef3014 : vtkGenericOpenGLRenderWindow::Render() [(libvtkRenderingOpenGL2-8.2.so.1) ???:-1]
0x7f914bc9a0 : vtkRenderWindowInteractor::Render() [(libvtkRenderingCore-8.2.so.1) ???:-1]
0x7f91645148 : vtkInteractorStyleTrackballCamera::Rotate() [(libvtkInteractionStyle-8.2.so.1) ???:-1]
0x7f91644690 : vtkInteractorStyleTrackballCamera::OnMouseMove() [(libvtkInteractionStyle-8.2.so.1) ???:-1]
0x7f91521024 : vtkInteractorStyle::ProcessEvents(vtkObject*, unsigned long, void*, void*) [(libvtkRenderingCore-8.2.so.1) ???:-1]
0x7f921b73e4 : vtkCallbackCommand::Execute(vtkObject*, unsigned long, void*) [(libvtkCommonCore-8.2.so.1) ???:-1]
0x7f9240354c : ??? [(???) ???:-1]
0x7f92403c8c : vtkObject::InvokeEvent(unsigned long, void*) [(libvtkCommonCore-8.2.so.1) ???:-1]
0x7f916a9870 : QVTKInteractorAdapter::ProcessEvent(QEvent*, vtkRenderWindowInteractor*) [(libvtkGUISupportQt-8.2.so.1) ???:-1]
0x7f916d47d0 : QVTKOpenGLWindow::ProcessEvent(QEvent*) [(libvtkGUISupportQt-8.2.so.1) ???:-1]
0x7f916d462c : QVTKOpenGLWindow::mouseMoveEvent(QMouseEvent*) [(libvtkGUISupportQt-8.2.so.1) ???:-1]
0x7f8f22bce8 : QWindow::event(QEvent*) [(libQt5Gui.so.5) ???:-1]

```

I am using in::

- Ubuntu 18.04
- Qt 5.9.5
- PCL 1.12
- Vtk 8.2.0

Please give me any suggestions.

Best regards,