@Suppaman The QML particle engine is implemented using scene graph APIs, so even if it was made available through C++, there is no way to use it in combination with a QGraphicsScene.
To implement particles manually in graphics view, you need to implement it as a single particlesystem item. Using a unique item per particle and animation objects to control each of those will be far to heavy unless you want to limit yourself to 100 particles.
Instead, use a custom item with a paint() function that makes use of the QPainter::drawPixmapFragments() function. That allows you to create an array with an entry for each particle which can be drawn in a single QPainter call. If your graphics view is running on an OpenGL viewport, that translates to a single glDrawXxx call which will give you very good performance.
Another option for a large amount of particles would be do native GL with the use of QPainter::beginNativePainting()/endNativePainting(), again assuming that your graphics view is rendering to a GL viewport.