Not everything Google does with its mapping technology is great - and investigations are continuing into some of the worst examples.

But privacy concerns aside, Google Maps and Google Earth have pretty much revolutionised maps online - and it looks like that's not stopping any time soon.

At its I/O developers conference, where the search giant also announced new tablets, augmented reality glasses and media streaming tech, Google unveiled the latest upgrade to its mapping technology: 3D maps of a quality never seen before.

The new 3D maps feature high resolution images, shadows and smooth 3D graphics, and have been created for many American cities (Boulder, Boston, Charlotte, Lawrence, Los Angeles, Long Beach, Portland, San Antonio, San Diego, Santa Cruz and Tampa) as well as Rome in Italy.

The tech is so sophisticated it can build up 3D models of elements as subtle as trees, all by using 45-degree photographs.

Take a look at the trailer above, and compare it to Apple's own 3D maps announced recently at its own developers conference below.

See Also: all the key announcements from Google I/O