Spiling sticks, joggle sticks and a “digital” rule

[hemmjo]

Peter, the video is not the best example of the process either. Imagine a much more complex shape. For example fitting a counter top into the galley of a boat. Or fitting a V-berth into the bow of a boat. You want it to fit snug against the side to things do not slip between it and the side of the boat. There are no straight lines. There is nothing good to use for reference points. You just have to "map out" the size and shape by creating your own reference points.

The scribing technique you describe certainly works in a lot of situations, but that is dependent on the angle of the stick, or scribe or compass, etc remaining constant to in relation to the surface being copied.