Hi Steve Park
If it’s a structured light scanner setup, then you cannot expect good results from pure photogrammetry solution with just 18 cams.
You can use control point workflow but I can say right now the results will be very poor… For proper photogrammetry build you need at least 64 cameras to get good results…
If it’s possible, use carton boxes with newspaper on them to get better alignment results, then use the XMPs to transfer alignment to other datasets + set proper scale.