When I turn on 3D acceleration in Virtual Box 5.0.20 on my Windows 7 x64, QT creator starts up with an inoperable screen on my guest Ubuntu 14.04. Either only parts are visible or the screen gets all white.
3D acceleration seems to work in general. I ticked the checkbox and re-installed the guest editions. After a reboot of the VM, unity runs smoother and I can start any program except QT Creator.