Page 4 - i1052-5173-26-8
P. 4

Virtual Rocks

GSA TODAY | AUGUST 2016  Declan G. De Paor, Department of Physics and Department of             courses, and social media pages. Reynolds et al. (2002) and
                         Ocean, Earth, and Atmospheric Sciences, Old Dominion                   Bennington and Merguerian (2003) used QuickTime Virtual
                         University, Norfolk, Virginia 23529, USA, ddepaor@odu.edu              Reality (QTVR) to display interactive digital specimens. The
                                                                                                Smithsonian Museum has a large collection of scanned 3D
                         ABSTRACT                                                               objects (Smithsonian, 2016), and the British Geological Survey
                                                                                                (2016) has assembled more than 1,800 virtual fossils. Numerous
                           Three-dimensional digital models of geological objects are rela-     LiDAR models of outcrops have been made (Clegg et al., 2005;
                         tively easy to create and geolocate on virtual globes such as Google   McCaffrey et al., 2008; Buckley et al., 2010; see also Passchier,
                         Earth and Cesium. Emerging technologies allow the design of            2011, and VOG, 2016).
                         realistic virtual rocks with free or inexpensive software, relatively
                         inexpensive 3D scanners and printers, and smartphone cameras             More recently, geoscientists have created many virtual speci-
                         linked to point-cloud computing services. There are opportunities      mens for paleontological functional analysis, digital exchange of
                         for enhanced online courses, remote supervision of fieldwork,          research data, and teaching in a range of geoscience subdisci-
                         remote research collaboration, and citizen-science projects, and       plines. For example, Pugliese and Petford (2001) revealed 3D melt
                         there are implications for archiving, peer-review, and inclusive       topology of veined micro-diorite, and Bates et al. (2009) estimated
                         access to specimens from inaccessible sites. Virtual rocks can be      dinosaur bone mass from models.
                         gradually altered to illustrate geological processes such as weath-
                         ering, deformation, and metamorphic mineral growth. This paper           Modelers have long used 3D scanners, and, more recently, 3D
                         surveys applications in a wide range of geoscience subdisciplines      printers (Hasiuk, 2014) to create ever-more sophisticated virtual
                         and includes downloadable examples. Detailed instructions are          objects. Cohen et al. (2010) reconstructed archaeological vessels
                         provided in the GSA Supplemental Data Repository1.                     from virtual ceramic shards, harnessing the computer’s power to
                                                                                                solve 3D jigsaw puzzles. Engineering geologists Dentale et al.
                         INTRODUCTION                                                           (2012) used FLOW-3D® software to test a virtual breakwater built
                                                                                                out of individual virtual stones and accropodesTM. Medical
                           In recent decades, numerous virtual field trips have been            CT-scanning methodologies were used by Hoffmann et al. (2014)
                         created to simulate in-person field excursions; however, one           to study buoyancy in virtual cephalopods, by Carlson et al. (2000)
                         aspect of physical fieldwork is not commonly replicated: virtual       for igneous texture studies, and by Pamukcu et al. (2013) to
                         explorers do not often return to their computer desktops with          examine glass inclusions in quartz crystals. Rohrback-Schiavone
                         collections of virtual rocks! There are multiple justifications for    and Bentley (2015) employed GIGAmacroTM hardware to create
                         creating interactive 3D digital models of rocks, minerals, fossils,    grain-scale sedimentological models. Root et al. (2015) compared
                         drill core, geo-archaeological objects, and outcrops. For example,     models of Neolithic monuments in Ireland and the Middle East,
                         one can (i) reveal 3D features hidden inside solid specimens; (ii)     while Mounier and Lahr (2016) created a 3D model of the skull of
                         archive samples destined for destructive testing; (iii) prepare for    the common ancestor of humans and Neanderthals. Structural
                         field trips and reinforce learning and retention after the fact; (iv)  geologists Thiele et al. (2015) gained new insights into en échelon
                         aid peer-review and supplement electronic publications; (v) give       vein formation, and Favalli et al. (2012) modeled outcrops, a
                         access to geological materials for disabled and other non-tradi-       volcanic bomb, and a stalagmite. They concluded that the quality
                         tional students; and (vi) provide access to collections locked away    of virtual outcrops or specimens is comparable to LiDAR outcrops
                         in storage drawers, given that museums and other repositories          or laser-scanned specimens, respectively.
                         display only a small fraction of their holdings.
                                                                                                  In recent years, the most exciting developments in 3D modeling
                           The concept of a virtual specimen is not new. Following the          include the availability of smartphone apps and associated point-
                         mechanical tomography of Sollas (1904), Tipper (1976) used a           cloud computing services that non-specialists can quickly master.
                         grinding wheel to serial-section fossils. He traced outlines with a    The purpose of this paper is to highlight the recent, current, and
                         digitizing tablet, created 3D models with a mainframe computer,        potential future role of virtual specimens in diverse aspects of
                         and interacted with them using a graphics storage tube (relatively     geoscience education and research.
                         youthful readers can image-google “graphics storage tube”),
                         exploring previously hidden inner surfaces.                            CREATING VIRTUAL SPECIMENS WITH SKETCHUP

                           Virtual geological collections already exist online, and readers       Virtual specimens can be created with a digital camera and
                         may simply link content to their own virtual field trips, online       SketchUp (2016). SketchUp exports a model as a COLLADA file
                                                                                                optionally zipped with a KML document and one or more texture

                            GSA Today, v. 26, no. 8, doi: 10.1130/GSATG257A.1.

                            1 GSA Supplemental Data Repository Item 2016173, detailing techniques for creating virtual specimens along with figure animations, is online at www.geosociety.org/
                            pubs/ft2016.htm. If you have questions, please contact GSA Today, P.O. Box 9140, Boulder, CO 80301-9140, USA; gsatoday@geosociety.org.

                       4
   1   2   3   4   5   6   7   8   9