How to render only in a single QQuickItem?

[julienchz]

Hello, I use VTK9 (QQmlVTKPlugin) in a Qt6 QML project to add a 3D viewer, my rendering is done in a QQuickItem. To synchronize the main thread and the render thread, I use my appication window :

connect(m_window, &QQuickWindow::beforeRendering, m_renderer, &ViewerRenderer::init, Qt::DirectConnection);
connect(m_window, &QQuickWindow::beforeRenderPassRecording, m_renderer, &ViewerRenderer::paint, Qt::DirectConnection);
connect(m_window, &QQuickWindow::beforeSynchronizing, m_renderer, &ViewerRenderer::sync, Qt::DirectConnection);

But with this method, all updates of a QQuickItem run a render of my 3D viewer. Is it possible to use the same synchronization system but to render only in the chosen QQuickItem with VTK or should I use another way ?

Thanks for your help