That approach has been used for almost 10 years now, using HD cameras at first and higher resolutions as they became available. This is largely based on Paul Debevic's work and as I recall was used as early as 2003 on "Matrix Reloaded."
BTW, any time you hear that projection mapping is the "final step," be aware that this is rarely the case. All of these type of effects are tweaked to death and often fixed by hand, because those "automated" approaches rarely work as seamlessly as many would like to believe - and that very much includes the 3D tracking of replacement objects.



