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3D modeling technology and lithic analysis at Wadi al-Hasa locality 623X, Jordan

3D modeling technology and lithic analysis at Wadi al-Hasa locality 623X, Jordan. Julien Riel-Salvatore Department of Anthropology & Archaeological Research Institute Arizona State University. What is PRISM?. Partnership for Research In Stereo Modeling

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3D modeling technology and lithic analysis at Wadi al-Hasa locality 623X, Jordan

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  1. 3D modeling technology and lithic analysis at Wadi al-Hasa locality 623X, Jordan Julien Riel-Salvatore Department of Anthropology & Archaeological Research Institute Arizona State University

  2. What is PRISM? • Partnership for Research In Stereo Modeling • 3D Knowledge and Distributed Intelligence Project 3DK – April 17, 2002 (2)

  3. What’s the link b/w PRISM and refitting? • 3D perspective • Shape matching • Reduce time needed for refit • Data storage, sharing and management 3DK – April 17, 2002 (3)

  4. What is our goal? Plainly put, we want to automate the lithic refitting process. 3DK – April 17, 2002 (4)

  5. What is lithic refitting? • Re-assembling pieces of rock that were sequentially removed from a core by prehistoric toolmakers. 3DK – April 17, 2002 (5)

  6. Why bother with refitting? Problems currently associated with refitting • Very time consuming and labor intensive • Not useful for “big picture,” inter-site comparisons • Focus is on expedient technologies 3DK – April 17, 2002 (6)

  7. Why bother with refitting? “What do refitting studies tell us apart from the fact that we can do them and convince grant bodies to fund us?.... Have we in fact run out of things to do and questions to ask?” - Gamble 1999: xx. 3DK – April 17, 2002 (7)

  8. Why bother with refitting? “Refitting… can link artifacts together as behavior rather than simply assuming a relationship because they were recovered from a single level or from the same site”. - Lindly et al. 2000: 211 3DK – April 17, 2002 (8)

  9. Why bother with refitting? LITIHC REFITTING IS NOT AN END IN ITSELF!! Its results and justification must always be linked to broader questions related to prehistoric human behavior 3DK – April 17, 2002 (9)

  10. Potential benefits of refitting • Understand prehistoric technology and economic behavior (how stone was used and managed) 3DK – April 17, 2002 (10)

  11. Potential benefits of refitting 2) Understanding taphonomy (archaeological site formation processes and post-depositional processes affecting the placement and morphology of artifacts) 3DK – April 17, 2002 (11)

  12. Potential benefits of refitting 3) Testing preconceived ideas about technology and typology and the relationship between the two (e.g., Volkman 1983, Marks & Volkman 1987). 3DK – April 17, 2002 (12)

  13. How are we going about it? • Analyzing a bona fide archaeological assemblage that has previously been refitted  Locality 623X from the Wadi Hasa (Jordan), excavated by G.A. Clark (ASU) and colleagues 3DK – April 17, 2002 (13)

  14. Wadi Hasa 623X Cores Total of 10 refitted cores; 5 used for this project. Core C 33 pieces Core H 6 pieces Core A 16 pieces Core F 7 pieces Core E 23 pieces 3DK – April 17, 2002 (14)

  15. Why refitted material? • Using previously refitted cores because: 1) we know exactly which pieces are supposed to fit with which; 2) we have an estimate, in man-hours, of the time investment required by manual refitting to compare our results to. 3DK – April 17, 2002 (15)

  16. Digitizing Process 1) Scanning: On Cyberware M15 Laser Digitizer 3DK – April 17, 2002 (16)

  17. Digitizing Process 2) Generating 3D data Point cloud Triangulated mesh Smooth surface 3DK – April 17, 2002 (17)

  18. Digitizing Process 3) Cleaning up and decimation, using Raindrop Geomagic 4.0 Clean up extraneous triangles Clean, decimated scan (10K triangles) Decimate clean scan (70K triangles) 3DK – April 17, 2002 (18)

  19. Digitizing Process 4) Generating regions and boundaries, using Watershed; Watershed threshold level can be adjusted for different degrees of resolution Threshold = 0.12 Threshold = 0.085 3DK – April 17, 2002 (19)

  20. Digitizing Process 5) Generating analytically meaningful areas, using Region Editor Volume (cm3) = 43.79348 Surface area (cm2) = 87.86601 Max length (cm) = 6.38181 Max width (cm) = 5.27742 Max height (cm) = 3.52001 3DK – April 17, 2002 (20)

  21. Digitizing Process 5) Generating analytically meaningful areas, using Region Editor Gaussian Curvature Absolute Curvature Mean Curvature RMS Curvature Kmax Curvature Kmin Curvature Surface Area (cm2) Selected region (Flake Scar 1- FS1) 3DK – April 17, 2002 (21)

  22. So… does it work? Sort of… One refit accomplished, but not very efficient.  15 minutes for ca. 1000 triangles, much user input.  Also, not realistic for archaeological pieces (1 to 1 match) 3DK – April 17, 2002 (22)

  23. So… does it work? In reality, we are dealing with two objects that each have a number of surfaces that may refit only partially 3DK – April 17, 2002 (23)

  24. Promising new approach Comparing series of point signatures on surfaces Program designed by M. Bae 3DK – April 17, 2002 (24)

  25. Other Applications Accurate measurements of specific areas on lithics that have never been accurately quantified (e.g., striking platforms) Region Area (cm2) = 0.80354 Striking platform (highlighted in orange) 3DK – April 17, 2002 (25)

  26. Other Applications Objective, accurate and tridimensional measures of artifact symmetry. Cross-section Vertical 3DK – April 17, 2002 (26)

  27. Other Applications Permanent, accurate, and flexible records of repatriated goods or those protected by National Antiquities Acts Goblet and effigy pot housed at the Archaeological Research Institute, Arizona State University 3DK – April 17, 2002 (27)

  28. Future Research • Actual refitting remains top priority • Other measurements can nonetheless already be put to profitable hypothesis-testing use 3DK – April 17, 2002 (28)

  29. Acknowledgements • NSF Grant IIS-998016 (3D Knowledge) • NSF Grant BNS-8406601 (G.A. Clark) • SSHRCC Grant 752-2001-0460 (J. Riel-Salvatore) • Many heartfelt thanks to fellow PRISM team members (M. Bae, D. Liu, P. McCartney, A. Razdan, A. Simon, M. Tocheri, D. Van Alfen, and others) 3DK – April 17, 2002 (29)

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