It's hard to describe the problem.therefore I show u some figures.
figure 1.
figure 2.
Figure 1 is one view of a tape.The solid lines are the features in the front of the tape and the dash lines are the features behind the tape,which we cannot see.
Figure 2 show u three loops in color(green,red and blue),which is just a part 2d loops of the tape.
Problem:Those loops in color is what I want to extract from the tape.
Hi Qui,
There seems no obvious link between the projected view and your contour selection other than that they part of the visible object lines.
You can only automate it if you can identify the object lines using an algorithm. You could add custom sketches in your model and name them Loop-01, Loop-02 or so and convert the model edges into the sketch as needed. If your sketches happen be on none-parallel planes then simply use the derived-sketch feature and put them all on the front plane.
Now you can automate. You can create drawing views and search for the model sketches named Loop-01 etc. Then show the sketch lines only and hide the body. All parametric.
just one way to do it