Determining spatial coordinates of a 3D reconstruction includes obtaining, from a first camera system, a first image comprising a first real object, obtaining, from a second camera system, a second image comprising a second real object associated with known geometric properties, wherein the first camera system and the second camera system have a known spatial relationship, and determining a scale of the face based on the second image and the known geometric properties of the at least part of the second real object. Determining the spatial coordinates of the 3D reconstruction also includes determining a pose of the first and second camera systems, and determining the spatial coordinates based on the pose of the first camera system and the scale of the at least part of the second real object.