The filament is designed to harden as it dries, so an object can be created layer by layer.

ECONOMIST: A new way to build complicated materials, micron by micron

Some experts have commented that Angel Ambush was not 'real' augmented reality at all, because the virtual angel was just a layer of video manipulated by a human operator, rather than an independent 3D object.

BBC: Augmented reality goes beyond gimmicks for business