• If a Mark on one photograph is referenced to a Mark on a second photograph, and
• If this Mark on the second photograph is referenced to a Mark on a third photograph,
• Then it follows that, the Marks on the first and third photographs will be referenced to each other.
For example, in the diagram below, Marked Points A and A' have been referenced to each other, and Marked Points B and B' have been referenced to each other. If you do the following:
• select Marked Point A,
• make Photo 1 the Reference Photograph,
• make Photo 3 the Active Photograph,
• reference Marked Point B to Marked Point A
then Marked Points A, A', B and B' will all refer to the same location in your 3D model. This point will show as having "4 references".
Additive referencing.
While the example shows Marked Points, this also applies to Edge Marks, Cylinder Marks, Curve Marks and Silhouette Marks.
Note: When properties (such as Material and Layer) of the objects being referenced differ, the property of the item with the most references will take precedence (e.g. if the layer of one Curve is different from the layer of the other Curve(s) being referenced, the layer of the Curve with the most associated Curve Marks becomes the final Curve's layer).