3D Scanning & Reverse Engineering Auguste Rodin's "The Thinker"

The Problem:

An early cast for Auguste Rodin’s “The Thinker” from his masterpiece “The Gates of Hell” had been owned by a family for many years, and was later sold for many millions at auction. Prior to sale, the owner wanted to have a 3D model of the statue for his own keepsake and possibly one day to recreate a lawful reproduction of the masterpiece. In the original bronze casting, a lead counterweight was installed into the back of this casting, in order to balance the weight of the frontward leaning masterpiece. By installing this weight, the sculpture was able to stand freely. However, in addition to providing our customer a 3D model for their own keepsake, we needed to figure out just how big this lead counterweight was.

Traditional Method:

For objects as detailed as sculptures like “The Thinker”, traditional measurement methods would have taken a very long time to achieve the accuracy needed to accomplish what they were seeking. There simply isn’t an easy way to replicate sculptures because of the complex curvatures and contours in the the design. Hand measurements are seemingly impossible to take because of the sculptures organic shape.

NeoMetrix Solution:

Using our MetraSCAN 750 3D scanner from Creaform, we are able to create a 3D duplicate of any physical object. With the MetraSCAN, we are able acquire 3D scan data with a level of accuracy of up to 0.030 mm or 0.0012 in just a matter of minutes. The MetraSCAN uses a bar with cameras and LED’s called the C-Track that is able to track the location of the handheld scanner. This setup method allows users to conduct scans on objects without having to place reference targets on the object’s surface.

Once scanning was completed, we designed in a space for the counterweight in the back. After this, we aligned it in Geomagic Design X. Design X is a complete software application for creating CAD models from 3D scan data. With Geomagic, you can open data from any 3D scanner and quickly create editable, parametric solid models of virtually any physical object. After aligning the scanned data, we cleaned it up in Geomagic Wrap. Wrap features intuitive “Exact Surfacing” tools which allow us to deliver a flawless 3D CAD model. We then delivered 2 cleaned STL files. One file had a solid bottom, and the other had the interior features we scanned.

NeoMetrix Advantage:

We elected to use the MetraSCAN to get a detailed scan of the entire exterior of The Thinker. We also scanned some of the interior. Because of the way the piece was designed (forward leaning), they needed to design in a lead counterweight in the back. We scanned the weight and surrounding area to be able to estimate the size of the weight and the thickness of the casting. We then delivered 2 cleaned STL files. One file had a solid bottom, and the other had the interior features we scanned.

3D scanning technology is becoming a huge resource in both sculpting and the preservation/restoration of historical artifacts. The ability to create a 3D model in a matter of minutes which can be used to archive sculptures and artifacts or 3D print or machine a replica, is a very advantageous tool.