How to detect: In the 3D View and photo projections, part of the 3D Bent Tube is missing and does not extend to the length of the marks in the photos.
How to solve: There are a number of possible reasons:
a) The marks on the photos may not extend all to the same place. The 3D Bent Tube requires at least two marks on a section of tube for the 3D for that section to be generated. E.g. if one mark extends to the tube attachment, but the other mark does not, then the 3D tube will end at the shorter mark’s end location.
b) If the tube is U shaped and only two photographs are used for marking, then the 3D Bent Tube will usually stop at the bigger bends in the tube. Add photo marks that also rotate around this newly oriented section of the tube. For example, the ‘horizontal’ part of the tube should be marked on two photos that are pointing down from the stern and bow (or mast) (for boat canvas tubes), and the ‘vertical’ parts of the tube should be marked on one or two photos that are dock level fore and aft (for boat canvas tubes). Also, try using the Reference Explorer to see how the reference line is perpendicular to the tube in the photos where it is referenced.
c) If one or more of the marks do not match the outline of the tube, then the solution may cause errors and fallout at an unexpected location along the tube. Zoom in to study the markings carefully. Drag existing marks, or add new edge or width points, to better define the tube shape.