Rotation of an image (in a loop) is not smooth although the fps is 60
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I tried two different possibilities.
First:
@Image
{
id: media_cover
source: "../images/media_cover.png"
smooth: true
rotation: 0
transformOrigin: Item.Center
}@@RotationAnimation
{
target: media_cover;
property: "rotation";
loops: Animation.Infinite;
from: 0;
to: 360;
duration: 8000
} @Second:
@ Image
{
id: media_cover
source: "../images/media_cover.png"
smooth: truetransform: Rotation { id: cover_rot origin.x: parent.width/2 origin.y: parent.width/2 angle: 0 }
}
@@NumberAnimation
{
target: cover_rot;
property: "angle";
loops: Animation.Infinite;
from: 0;
to: 360;
duration: 8000
}
@Both options don't work.
I tried it on windows xp, windows 7, i.MX53 with Qt 4.8 and also with Qt 5 Alpha. Everywhere with the same result.
Is it a known problem of Qt or rather someone knows a solution for this problem.
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AFAIK, it is a known problem, it was discussed a while ago on dev mailing list. Try porting to QtQuick2 if possible, just to see if it is still a problem there. On the other hand, animations are not smooth with QML2 on Linux... but maybe that was fixed, too.
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The perceived smoothness has to do with synchronization of the renderings with the updates of the screen by the underlying system (OpenGL, for instance). At least, that is how I understood the issue. See "this post":http://labs.qt.nokia.com/2010/12/02/velvet-and-the-qml-scene-graph/ for example.
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Thank You for your answers, I forget to say that i tried it with QtQuick 2.0, too. There is the same Problem.