Reverse engineering, or reengineering, is the name given to the process of creating an exact replica of a real object. This process is widely used in various industries — mechanical engineering, shipbuilding, and the aerospace industry. However, recently, reengineering has reached medicine and the biotech industry: for example, artificial bones for people with cancer are already being created with its help.

Reverse engineering begins with a 3D scan of the original. A 3D scanner can do almost all the work by itself — you just need to make sure that all the surfaces are in the frame. RangeVision 3D scanners are often involved in various reverse engineering projects. However, getting a scan is just the beginning, and it still needs to be turned into a working model.

It is to this stage of reverse engineering that we dedicate the new tutorials "Reverse Engineering for Beginners". In the first article of the series, we will show you how to turn raw scans into 3D models in SolidWorks. SolidWorks is one of the most popular CAD software, a standard in the design industry. It is often used specifically for reverse engineering tasks.

In this article we will tell you:

• How do I import 3D scanning data to SolidWorks for reverse engineering?
• How to perform reverse engineering in SolidWorks?

We will cover the following issues in detail:

• ScanTo3D add-on,
• automatic and controlled surface creation,
• how to use the Grid preparation wizard;
• how to use the surface wizard;
• surface modeling;
• solid body modeling;
• how to get a solid body from a grid.

We illustrate the stages of work with screenshots, and show the process on the video at the end of the article.

To demonstrate the capabilities of SolidWorks, we chose a simple organic object — a human tooth. In dentistry, reengineering technologies have found regular use: doctors make accurate plaster copies of patients' oral cavities for diagnosis and treatment. 3D scans of teeth are often transformed into 3D-printed dentures.: they fit perfectly into place.

Modern 3D scanners instantly take very accurate pictures. At the same time, past scan results are also saved on the doctor’s computer. According to this virtual medical history, the dentist checks the course of treatment. The 3D scan of the tooth, which will be discussed in the article, was made by a RangeVision scanner. Let’s figure out how to turn a raw scan into a solid object in SolidWorks.

First, let’s look at how to get the surface automatically. To upload the scan file to Solidworks, we will need the ScanTo3D plugin.
1. Make sure that the ScanTo3D plugin is installed and running.

2. Import the scan file.

3. From the context menu, launch Meshprep Wizard and follow its steps.

4. If necessary, change the coordinate system and remove unnecessary parts of the grid.

5. In the Simplification step, we will reduce the number of triangles to reduce the surface generation time.

6. The last step is to launch the SurfaceWizard wizard.

7. Turn on the automatic mode, to speed up the process, reduce the detail and generate the surface.

8. Red zones are surfaces with topology errors. We eliminate them manually by editing, adding or deleting control curves.

9. When all errors are fixed, we complete the wizard's work.

10. As a result, we got a solid body

The result of the algorithm may be inconvenient to edit. In this case, you can use a different method of surface construction — controlled. This method uses several controlled functions, the parameters of which the user adjusts to their needs.

1. Launch the surface wizard in controlled mode.

2. Redefine the color zones after automatic marking.

3. Select the Spline surface for the upper part of the tooth.

4. Edit the number of control curves.

5. We can change their position to correct the local curvature of the surface.

6. We are completing the work of the surface wizard.

7. We will build the side surface using the CurveWizard wizard

8. Select the Section method (by sections) and set the secant planes.

9. As a result, we have obtained curves of intersection of planes and grids, which we use to build a loft surface.

10. Extend the surface to the intersection with the previously obtained one and cut both along the border of the intersection

11. Let's build a sketch and crop the surface with it (you can also use the XY plane instead of the sketch).

12. Using the Filled surface function, we will close the gap with a patch surface.:

13. Sew all the surfaces using a Knit surface and get a solid body.:

14. Let's make sure that there is no cavity in the body using the type of section.

The resulting model is less accurate than with automatic construction, because it is built with assumptions. However, it is more suitable for further work and adjustments.

Reverse engineering took place: we received a detailed 3D model of a real organic object. We have learned how to create a solid in two different ways, which opens up many new possibilities. Now we can work with our model as with a body with volume: build a cross-section, print it on a 3D printer, or export it to another CAD program for further processing.

Other articles in the series:
Geomagic Design X: Reverse engineering of organic forms. 3D Scanning processing
Geomagic Design X: Grid alignment and editing
SolidWorks: reverse engineering of organic forms