This problem result is a project with none, few or mismatched 3D SmartPoints, and may also result in photos or sets of photos that were not oriented.
There was not enough overlap between photos.
Solution: Increase overlap by taking photos closer together, or add new photos where there are gaps in the sequence of photos. In a project where photos are taken 360 degrees around an object, ensure there is overlap, especially at the corners of a rectangular object. Try to have enough overlap so that some SmartPoints can be matched on 3 and more photos.
If the SmartMatch solution results in multiple independent sets of oriented photos (see Photo Orientation Status), manually marking and referencing new points on distinct features can help tie the sets together (ensure you meet Minimums).
If you are able to use Control Imports, you may be able to improve the solution by Using Control Points With SmartMatch.
Generally you'll want to rerun SmartMatch when new photos added (or if you want to try increasing density of SmartPoints - see SmartPoints Project Options Dialog), but in other cases, after adding manually marked and referenced points, you'll want to just re-process the project. No one solution fits all projects; some experimentation may be required. If you're having trouble with a seemingly well set up project, contact Technical Support.
The model object does not have enough texture to detect suitable features
Solution: Sometimes it’s possible to add texture to an object if it has a reflective or uniform surface. Temporarily applying a material like baby powder or paint splatter can add enough features to a surface so that enough SmartPoints can be marked. Perhaps the surface can be photographed with different lighting or with a higher resolution camera to improve texture capture.
The object moved between photographs.
Solution: The object needs to be steady during photography.