An actual point on an object that will be digitized or motion captured is referred to as a feature point. In Photo4D, this feature point has a corresponding entity that will be simply referred to as point.
If a specific feature point on the object appears in two or more images, one mark in each image is used to tag this point. We say these marks are for the same point. It is absolutely essential for points to be marked in two or more images in order for Photo4D to compute their coordinates.
In the Image Windows, a point is always identified as the current point for which all its marks are highlighted.
A regular mark is displayed with a white outline (default color). It has the shape of a tiny hourglass. The mark of the current point are solid purple (default color). The selected marks or points have green outline (default color). The default colors can be changed in the Configuration dialog. Mark Editing usually involves the current point.