There is a very limited amount of places that have accurate *vertical* mapping, and even less that have it on the level of buildings. Two, imagine a photo of a city panorama. I might be (trying to) point to a building but I will have always hundreds of potential points that will also be on the screen, between and around me and the target object. The further away your target is, the bigger this problem is - that's why I mentioned distance meters which would give you a pinpoint location of the target, not a line containing multiple possible targets. But, as said, if it's just 'hey what's this building I'm next to', you're good to go even with N810 class hardware.