So the mesh was not from a 3d scanner, but from 3d points measured using photogrammetry?

What are you using MeshMixer for?

There is software such as AGI's Photoscan that can create a mesh exclusively from photos (no laser needed), if you have enough suitable photos, and automatically construct the model. I am just starting to investigate this technique as an alternative to laser scanning.

I need to do some testing to determine what tolerances I could expect from a set of photos. There are a few variables that can impact the quality of the model.