Years ago, I played around with 3D modeling (and narrowly avoided a career at Matrox and Softimage in the process.) Building models was tedious: manipulating 3D space with two-dimensional tools like a mouse and a screen is tough. Software relies on all sorts of controllers, UI conceits, and tricks: rotating the onscreen image; holding down shift to move along the third dimension, and so on.
Google acquired Sketchup to help crowdsource 3D content for Google Earth largely because it was comparatively easy to use. But so far, we can’t work with 3D content in three dimensions.
That’s about to change: using modeling tools and AR visualization, designers can actually manipulate in three dimensions. Which will go a long way to making 3D models mainstream, unlocking all kinds of use cases.
Who knows, maybe soon, we’ll have opt-in vandalism, where taggers add 3D objects to the real world for those who want to see them.