I was trying to make a dice by using preserve-3d in css, just like here, however it appears that the display is not correct. And I opened that link in Qt Example [webengine]"Simplebrowser", same thing happened. I've tested Qt5.6.2(windows) and Qt5.9.1(mac), the problem persists.
In Qt5.5.1, it works fine.
|For Gerrit Dashboard: QTBUG-62112|
|203783,2||Fix upside down rendering of render-passes in software mode||5.9||qt/qtwebengine||Status: MERGED||+2||0|
|204418,4||Fix rendering of intersecting quads||5.9||qt/qtwebengine||Status: MERGED||-2||0|
|205865,2||Extract DrawQuad handling from DelegatedFrameNode::commit||5.9||qt/qtwebengine||Status: MERGED||+2||0|
|206121,2||Fix uninitialized member QSGClipNode::m_is_rectangular||5.9||qt/qtdeclarative||Status: MERGED||+2||0|
|206368,3||Fix viewport resizing bug in renderer||5.9.2||qt/qtwebengine||Status: MERGED||+2||0|