Consider the following snippet:
// standard boiler plate code for creating actors. renderer, etc
vtkNew<vtkCallbackCommand> callback;
callback->SetCallback(CallbackFunction);
renderer->AddObserver(vtkCommand::EndEvent, callback);
and
void CallbackFunction(vtkObject *caller, long unsigned int eventId,
void *vtkNotUsed(clientData),
void *vtkNotUsed(callData)) {
vtkRenderer *renderer = static_cast<vtkRenderer *>(caller);
double timeInSeconds = renderer->GetLastRenderTimeInSeconds();
double fps = 1.0 / timeInSeconds;
std::cout << "FPS: " << fps << std::endl;
std::cout << "Callback" << std::endl;
std::cout << "eventId: " << eventId << std::endl;
}
I have use this code in
qt with qml frontend
qt with qt fronted
VTK window manager@John Stone
jaswantp
August 12, 2024, 2:38pm
2
Hello @Behnam_Asadi
I understand what you mean. It may be trigerred because someone is invalidating the state of qml item causing it to repaint. Can you share a callstack so we know where the function call vtkRenderer::Render() comes from?
Thanks for quick reply, I paste here the entire code so you can experiment it:
cmake:
add_executable(vtk_forum_snippet src/vtk_forum_snippet.cpp qml.qrc )
target_link_libraries(vtk_forum_snippet PRIVATE ${VTK_LIBRARIES} ${PDAL_LIBRARIES} Qt${QT_VERSION_MAJOR}::Core Qt${QT_VERSION_MAJOR}::Quick Qt5::Widgets Qt${QT_VERSION_MAJOR}::Concurrent)
vtk_module_autoinit(TARGETS vtk_forum_snippet MODULES ${VTK_LIBRARIES})
cpp
#include <QQuickVTKItem.h>
#include <QQuickWindow>
#include <QVTKRenderWindowAdapter.h>
#include <QtGui/QGuiApplication>
#include <QtGui/QSurfaceFormat>
#include <QtQml/QQmlApplicationEngine>
#include <QtQuick/QQuickWindow>
#include <vtkActor.h>
#include <vtkCallbackCommand.h>
#include <vtkCommand.h>
#include <vtkConeSource.h>
#include <vtkInteractorStyleTrackballCamera.h>
#include <vtkMinimalStandardRandomSequence.h>
#include <vtkNamedColors.h>
#include <vtkNew.h>
#include <vtkPointData.h>
#include <vtkPoints.h>
#include <vtkPolyData.h>
#include <vtkPolyDataMapper.h>
#include <vtkPropPicker.h>
#include <vtkProperty.h>
#include <vtkRenderWindow.h>
#include <vtkRenderWindowInteractor.h>
#include <vtkRenderer.h>
#include <vtkSliderRepresentation2D.h>
#include <vtkSliderWidget.h>
#include <vtkSmartPointer.h>
#include <vtkSphereSource.h>
#include <vtkVertexGlyphFilter.h>
void CallbackFunction(vtkObject *caller, long unsigned int eventId,
void *vtkNotUsed(clientData),
void *vtkNotUsed(callData)) {
vtkRenderer *renderer = static_cast<vtkRenderer *>(caller);
double timeInSeconds = renderer->GetLastRenderTimeInSeconds();
double fps = 1.0 / timeInSeconds;
std::cout << "FPS: " << fps << std::endl;
std::cout << "Callback" << std::endl;
std::cout << "eventId: " << eventId << std::endl;
}
struct MyVtkItem : public QQuickVTKItem {
vtkUserData initializeVTK(vtkRenderWindow *renderWindow) override {
// Create a cone pipeline and add it to the view
vtkNew<vtkConeSource> cone;
vtkNew<vtkPolyDataMapper> mapper;
mapper->SetInputConnection(cone->GetOutputPort());
vtkNew<vtkActor> actor;
actor->SetMapper(mapper);
vtkNew<vtkRenderer> renderer;
renderer->AddActor(actor);
renderer->ResetCamera();
renderWindow->AddRenderer(renderer);
vtkNew<vtkCallbackCommand> callback;
callback->SetCallback(CallbackFunction);
renderer->AddObserver(vtkCommand::EndEvent, callback);
return nullptr;
}
bool event(QEvent *event) override {
qDebug() << "-------------------------";
QEvent::Type type = event->type();
switch (type) {
case QEvent::None:
qDebug() << "None";
case QEvent::Timer:
qDebug() << "Timer";
case QEvent::MouseButtonPress:
qDebug() << "MouseButtonPress";
case QEvent::MouseButtonRelease:
qDebug() << "MouseButtonRelease";
case QEvent::MouseButtonDblClick:
qDebug() << "MouseButtonDblClick";
case QEvent::MouseMove:
qDebug() << "MouseMove";
case QEvent::KeyPress:
qDebug() << "KeyPress";
case QEvent::KeyRelease:
qDebug() << "KeyRelease";
case QEvent::FocusIn:
qDebug() << "FocusIn";
case QEvent::FocusOut:
qDebug() << "FocusOut";
case QEvent::Enter:
qDebug() << "Enter";
case QEvent::Leave:
qDebug() << "Leave";
case QEvent::Paint:
qDebug() << "Paint";
case QEvent::Move:
qDebug() << "Move";
case QEvent::Resize:
qDebug() << "Resize";
case QEvent::Close:
qDebug() << "Close";
// Add other cases as needed
default:
qDebug() << QString("Unknown(%1)").arg(static_cast<int>(type));
}
return QQuickVTKItem::event(event);
}
QSGNode *updatePaintNode(QSGNode *q, UpdatePaintNodeData *u) override {
std::cout << "updatePaintNode" << std::endl;
return QQuickVTKItem::updatePaintNode(q, u);
}
bool isTextureProvider() const override {
std::cout << "isTextureProvider" << std::endl;
return QQuickVTKItem::isTextureProvider();
}
// QSGTextureProvider* textureProvider() const override{}
// void releaseResources() override{}
};
int main(int argc, char *argv[]) {
QQuickVTKItem::setGraphicsApi();
#if QT_VERSION < QT_VERSION_CHECK(6, 0, 0)
QCoreApplication::setAttribute(Qt::AA_EnableHighDpiScaling);
#endif
QGuiApplication app(argc, argv);
qmlRegisterType<MyVtkItem>("com.vtk.example", 1, 0, "MyVtkItem");
QQmlApplicationEngine engine;
engine.addImportPath("/home/behnam/usr/lib/qml");
engine.load(QUrl("qrc:/qml/vtk_basic.qml"));
if (engine.rootObjects().isEmpty())
return -1;
return app.exec();
}
qml (vtk_basic.qml):
import QtQuick 2.9
import QtQuick.Window 2.2
import com.vtk.example 1.0
Window {
id: win
visible: true
width: 640
height: 640
title: qsTr("Hello World")
Rectangle {
anchors.fill: parent
color: "darkseagreen"
}
Rectangle {
id: r
border { width: 5; color: "steelblue" }
radius: 5
color: "hotpink"
anchors.fill: parent
anchors.margins: 100
MyVtkItem {
id: vtk
anchors.fill: parent
anchors.margins: 5
opacity: 0.7
}
}
}
qml.qrc
<RCC>
<qresource prefix="/">
<file>qml/vtk_basic.qml</file>
</qresource>
</RCC>
BTW, Qt5.15 and VTK9.3