Qt3D problem

In this code

Code:

---

import QtQuick 1.0
import Qt3D 1.0
 
Viewport {
    width: 640; height: 480
    Item3D {
        id: teapot
        mesh: Mesh { source: "teapot.bez" }
        effect: Effect {}
    }
}

---

i have that error

Code:

---

GL graphics system is not active; cannot use 3D items

---

Are you running this in QML Viewer? If so do you have the -graphicssystem opengl command line argument?

Without it you won't be running in GL mode, and will get this error.

I have been stumbling upon the same error while running the car 3D demo code. kindly help