Current Research: 3D scanning of Obsidian Bifaces


Current Research: 3D scanning of Obsidian Bifaces

Today we have a guest blog submission by Madelyn Green, a graduate student from Ohio State University.  We recently had the pleasure of working with Madelyn to get 3D scans of large obsidian bifaces from the Hopewell Mound Group.

Thanks Madelyn!

Madelyn showing how the scanning is done.

Three-dimensional replication of objects has been possible since the times of Ancient Egypt when 

priests created plaster casts of mummified heads. Thousands of years later, such messy methods are no longer necessary to transform real life objects into 3D visualizations. In the early 1980s, technologically advanced methods of 3D scanning began to emerge with contact probes. Designed to digitally reconstruct an object based off of data points, the probe system required that physical points on the object be recorded via an electronic probe. For instance, if attempting to translate a real-life bone into a digitally constructed 3D image, a researcher would press the probe against points on the actual bone until the program had enough points to build a 3D model within the computer from those established data points. While effective, the probe system required labor intensive procedures and was restricted by the availability of storage space for all the data points from the object.

The technological revolution in the late 1980s, 1990s, and early 2000s eradicated the probe-point technology from the 3D research world. From then on, scanners have been at the forefront of 3D technology. By combining infrared lasers, two-dimensional cameras, and point-recognition software (similar, though more refined than the probe system software), designers have constructed a machine that can independently capture and construct a 3D image of real-life objects. The process of building the 3D image has become relatively straightforward for the user, as most of the coding designed by the software programmers enable to machine to scan and collects the data points from the object without user interference.

When an object is placed in front of the 3D scanner, the user orients the optimal settings for the particular object being scanned. For example, with the Hopewell obsidian pieces from the Ohio History Connection exhibit, the scanning settings needed to be manipulated to ensure a clear and accurate representation of the obsidian materials. This required the user to adjust the photographic lighting, the level of detail wanted (i.e. low, standard, or high-definition picture quality), and the number of scans of the object (i.e. a 360° rotation of the obsidian spearhead or a single scan of a single side of the spearhead). For the obsidian pieces, the level of detail was the most important feature to attend to. Picture quality refers to the amount of reference points that the infrared lasers pick up from the spearhead during one scan. Low quality scans therefore have a fewer number of points per inch than an HD scan. Coupled with selecting the camera preference for dark objects, the obsidian pieces were scanned, points collected, and the point-data was compiled using the program software to be reconstructed digitally within the computer.

The implications that 3D scanning and modeling technology have on the academic world are profound. In anthropology for example, artifacts, skeletal remains, and a plethora of other material remains can be transformed into 3D images and utilized by researchers without destroying, harming, or detrimentally affecting the real-life objects themselves. In the Ohio State University Bioarcheology Laboratory, dental casts are in the process of being converted into 3D models. Eventually, all 1500 dental casts will be readily available through a database through which researchers can gain access and utilize the scans to form, test, and conclude research questions about teeth and populations. Additionally, the primatology portion of the OSU Anthropology Department has been using 3D scans to measure features on brachiating primate bones. Through the 3D image gleamed through the scanning process, researchers are able to ensure precise and accurate measurements of the specimens.

3D technology is constantly changing, improving, and condensing. New scanners are capable of producing HD 3D images or large objects in as little as half an hour. Mobile phone apps, such as 123 Cache are tailored to be user friendly, fast, and easy to edit. The 3D revolution is in full-swing and has incredible gains when applied to academic research. 

Posted February 18, 2016
Topics: American Indian HistoryArchaeology

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