When i use vtkWorldPointPicker to get world position from display coordinates;
it say that:
2021-04-18 13:16:52.518 ( 18.223s) [ 6D679800] vtkOpenGLState.cxx:203 WARN| Error in cache state for GL_READ_FRAMEBUFFER_BINDING
2021-04-18 13:16:52.522 ( 18.226s) [ 6D679800] vtkOpenGLState.cxx:265 WARN| at stack loc
0x7f0e72bf220a : ??? [(???) ???:-1]
0x7f0e72bece9f : vtksys::SystemInformation::GetProgramStack[abi:cxx11](int, int) [(libvtksys-9.0.so.1) ???:-1]
0x7f0e74f6a491 : vtkOpenGLState::CheckState() [(libvtkRenderingOpenGL2-9.0.so.1) ???:-1]
0x7f0e74f6b671 : vtkOpenGLState::vtkBindFramebuffer(unsigned int, vtkOpenGLFramebufferObject*) [(libvtkRenderingOpenGL2-9.0.so.1) ???:-1]
0x7f0e74f3f720 : ??? [(???) ???:-1]
0x7f0e74f44243 : vtkOpenGLRenderWindow::GetZbufferData(int, int, int, int, float*) [(libvtkRenderingOpenGL2-9.0.so.1) ???:-1]
0x7f0e74f445f8 : vtkOpenGLRenderWindow::GetZbufferData(int, int, int, int) [(libvtkRenderingOpenGL2-9.0.so.1) ???:-1]
0x7f0e7536ffd8 : vtkRenderer::GetZ(int, int) [(libvtkRenderingCore-9.0.so.1) ???:-1]
0x7f0e753d7723 : vtkWorldPointPicker::Pick(double, double, double, vtkRenderer*) [(libvtkRenderingCore-9.0.so.1) ???:-1]
0x564cb87f308b : ??? [(???) ???:-1]
0x7f0e753ead4e : vtkInteractorStyle::ProcessEvents(vtkObject*, unsigned long, void*, void*) [(libvtkRenderingCore-9.0.so.1) ???:-1]
0x7f0e76e102ef : vtkCallbackCommand::Execute(vtkObject*, unsigned long, void*) [(libvtkCommonCore-9.0.so.1) ???:-1]
0x7f0e7701c794 : ??? [(???) ???:-1]
0x7f0e7701ccf1 : vtkObject::InvokeEvent(unsigned long, void*) [(libvtkCommonCore-9.0.so.1) ???:-1]
0x7f0e75db903b : QVTKInteractorAdapter::ProcessEvent(QEvent*, vtkRenderWindowInteractor*) [(libvtkGUISupportQt-9.0.so.1) ???:-1]
0x7f0e75dc2e4f : QVTKRenderWindowAdapter::handleEvent(QEvent*) [(libvtkGUISupportQt-9.0.so.1) ???:-1]
0x7f0e75dbd11d : QVTKOpenGLNativeWidget::event(QEvent*) [(libvtkGUISupportQt-9.0.so.1) ???:-1]
0x7f0e745f1a7c : QApplicationPrivate::notify_helper(QObject*, QEvent*) [(libQt5Widgets.so.5) ???:-1]
0x7f0e745f9208 : QApplication::notify(QObject*, QEvent*) [(libQt5Widgets.so.5) ???:-1]
0x7f0e73637ae8 : QCoreApplication::notifyInternal2(QObject*, QEvent*) [(libQt5Core.so.5) ???:-1]
0x7f0e745f81fa : QApplicationPrivate::sendMouseEvent(QWidget*, QMouseEvent*, QWidget*, QWidget*, QWidget**, QPointer&, bool, bool) [(libQt5Widgets.so.5) ???:-1]
0x7f0e74649e41 : ??? [(???) ???:-1]
0x7f0e7464ca8b : ??? [(???) ???:-1]
0x7f0e745f1a7c : QApplicationPrivate::notify_helper(QObject*, QEvent*) [(libQt5Widgets.so.5) ???:-1]
0x7f0e745f8cb0 : QApplication::notify(QObject*, QEvent*) [(libQt5Widgets.so.5) ???:-1]
0x7f0e73637ae8 : QCoreApplication::notifyInternal2(QObject*, QEvent*) [(libQt5Core.so.5) ???:-1]
0x7f0e73ce6ad8 : QGuiApplicationPrivate::processMouseEvent(QWindowSystemInterfacePrivate::MouseEvent*) [(libQt5Gui.so.5) ???:-1]
0x7f0e73ce7fb5 : QGuiApplicationPrivate::processWindowSystemEvent(QWindowSystemInterfacePrivate::WindowSystemEvent*) [(libQt5Gui.so.5) ???:-1]
0x7f0e73cc4bdb : QWindowSystemInterface::sendWindowSystemEvents(QFlagsQEventLoop::ProcessEventsFlag) [(libQt5Gui.so.5) ???:-1]
0x7f0e69f31e7a : ??? [(???) ???:-1]
0x7f0e6e61117d : g_main_context_dispatch [(libglib-2.0.so.0) ???:-1]
0x7f0e6e611400 : ??? [(???) ???:-1]
0x7f0e6e6114a3 : g_main_context_iteration [(libglib-2.0.so.0) ???:-1]
0x7f0e7369055c : QEventDispatcherGlib::processEvents(QFlagsQEventLoop::ProcessEventsFlag) [(libQt5Core.so.5) ???:-1]
0x7f0e73636502 : QEventLoop::exec(QFlagsQEventLoop::ProcessEventsFlag) [(libQt5Core.so.5) ???:-1]
0x7f0e7363f430 : QCoreApplication::exec() [(libQt5Core.so.5) ???:-1]
0x564cb87f41dd : ??? [(???) ???:-1]
0x7f0e72e6c0b3 : __libc_start_main [(libc.so.6) ???:-1]
0x564cb87ec64e : ??? [(???) ???:-1]