QGraphicsItem disappeare during rotation around Qt::XAxis

Hi,
I can't find the reason, why my object disappearing during transformation around the XAxis.
I am showing here the short code which better expain what I mean.
When I use QTransform on the scene and rotate the view, then if i use high angle the QGraphicsRectItem disappeare.
Or if I make the view window height bigger, which anybody who would help me can try in this small app.

Code:

---

#include <QApplication>
#include <QGraphicsView>
 
 
int main(int argc, char **argv)
{
    QApplication app(argc, argv);
 
    QGraphicsScene scene;
    scene.addRect(QRectF(0,0,100,100), QPen(), QBrush(QColor(Qt::red)));
    QGraphicsView view(&scene);
    view.show();
 
    QTransform transform;
    transform.rotate(80, Qt::XAxis);
    view.setTransform(transform);
 
    return app.exec();
}

---

I can see the item just fine. Bear in mind that graphics items are flat, if you rotate them 90 deg. they will disappear because their z size is 0.

Hi,
did you try to change window size? if I make it vertically bigger the item disappear and again appear when i make the window smaller.
If you tried it and you still can see it then the problem will be somewhere else, but I have no idea where. I was trying on the different comps with kubuntu and and also on windows. The problem was on all of them.

Hi, you should know what really you want to do. If you only want to rotate the rect, just use QGraphicsItem::rotate(). The transform will rotate the whole coordinate.

Hi,
the code above is just simple example to demonstrate what I mean. I am doing chessboard, so there should be option to zoomin and out and to rotate it. But then is coming the problem which I described above.

Radek

so looks like it was a bug, i have tried on qt 4.5 and the transformation is fine