The laser needs to be aimed at each point of interest. The system can track multiple laser points simultaneously with one pair of cameras, but there's a tradeof

The laser needs to be aimed at each point of interest. The system can track multiple laser points simultaneously with one pair of cameras, but there's a tradeoff with quality (because essentially the camera's field of view is being divided into slices, one for each laser point). So you've got a small number of virtual contact microphones you can point at a surface, not a video where you can see the vibration at each point.