Polar grid doesn't work on widget-side. This can be seen surface tester where the radial grid is not visible at all., Besides, the radial labels seem to overlap with background. Similar grid issues happen with scatter but in addition the points are positioned incorrectly. On qml-side it almost works correctly in surfacegallery's spectrogram. The grid shouldn't have those vertical lines. Compared to qmlsurface, qmlscatter doesn't work at all. However, the angular grid seems to be fairly good, albeit quite small.