(2) USING THE SCAN DATA AS REFERENCE
A 3D scanner can obtain 3D data from the areas where its light can reach. This means that sometimes deep grooves and ridges are unable to be scanned in complex objects. In this case, the 3D data can be modified or reverse engineered before use.
Reverse engineering refers to the process of re-modeling with the use of scan data as a reference. Just as one would copy a drawing by placing an original underneath and tracing it, with 3D modeling it much more convenient and precise to use the 3D data as a reference point. Using a 3D scanner also elminates the need for photographs and size measurements, a significant time saving for designers.
If we look closer at the reverse engineering process, the first step is to set the scan data at the center and draw the guideline (Image 5) followed by modeling the prong and surface according to the scan data (Image 6). Also, it is much easier to model in spread shape when working with rings. We can see the overlapped image of the original scan data and the reverse engineered data -- appearing to be identical. Moreover, we can see that the final 3D printed piece is identical in terms of shape and proportion to the original.
(3) USING THE SCAN DATA SELECTIVELY
Lastly, we can use a combination of the above two processes -- using the scan data as is (1) and also use the scan data as a reference (2) to be used when reverse engineering in needed.
1) cut off the reverse engineering part from the scan data <Image 8>. 2) Re-model the reverse engineering part. 3) Combine the scan data and reverse engineering data <Image 9>.