GENUINE OR REPRODUCTION: A COMPARISON OF PHOTOGRAMMETRY AND 3D SCANNING TECHNIQUES

Advancements in technology associated with 3D imaging for both print and digital applications are transforming many aspects of geology. Museums, researchers, and educators are now using 3D models to depict and reproduce fossils, minerals, and crystals for study, thereby reducing the risk of damage to valuable original specimens. This project evaluates readily-available digital imaging methods to determine the process for obtaining the best quality 3D models for printing. The criteria included cost effectiveness, quality of digital images and prints, length of time of each method, and availability of software and hardware. Several methods utilize smartphone cameras or standalone digital cameras to take overlapping photos of an entire specimen (fossil or mineral). Then, a variety of digital 3D models were created using multiple image-manipulation software programs (AgiSoft, and Autodesk ReMake). The digital models were then sent to a 3D printer for printing. Another method made use of a 3D-scanner (NextEngine 3D Scanner) rather than static images from cameras -- a specimen was placed on a rotating pedestal and laser scanners swept across the specimen as cameras within the scanning unit determined how much distortion was created. The scanner data was imported into software (ScanStudio 3D) that then created a point cloud of the specimen. From the point cloud a 3D model was created for viewing on the computer, or, ultimately, for 3D printing. For this study the quality of the digital images and printed reproductions that were derived from the multiple methods were compared. In the final analysis of the various 3D models (printed and digital) the determination was made that the 3D scanning process produced the better quality facsimiles. However, under the pre-defined criteria, the 3D scanning method was not cost effective, and the process was very time consuming. While the methods that involve making point clouds from the overlapping static images did not produce the best quality 3D models (printed and digital), these methods were cost effective, the processes were easy to learn and were not as time consuming, and the software and hardware were more readily available.