#Arm bones 123d models

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Arm bones 123d models

#Arm bones 123d models portable

Clinical CTs produce a stack of images with a spatial resolution of maximal 0.5 mm. It allows one to investigate both internal and external structures of objects and, hence, is most useful for hidden and internal structures, such as bones in mummies, cremated remains in urns, trabecular bone structure, or endocranial morphology. Including metadata of the internal geometry of the camera used to take the pictures (focal length, focal ratio, lens distortion, etc.) helps to scale the model accurately.ĬT scanning is a method to produce volumetric data from X‐ray images taken from different angles. In contrast to 3D surface scanners, which are calibrated and provide both shape and size information of the object, most photogrammetric methods capture only shape information unless the mesh is manually calibrated based on a scale (e.g., measurement tape) placed next to the object (Gonzáles et al., 2015). Photogrammetry has been applied in several research fields, ranging from anthropology (e.g., Adams et al., 2015 Fourie et al., 2011 Geoghegan, 1953 Ghoddousi et al., 2007 Martin & Knußmann, 1988), archaeology (e.g., Bouby et al., 2013 Counts et al., 2016 Grosman et al., 2008 Haukaas & Hoddgetts, 2016 Porter et al., 2016), medicine (e.g., Aldridge et al., 2005 Grant et al., 2019 Jayaratne et al., 2009 Plooij et al., 2009), and geomorphology (e.g., Heritage et al., 1998 Lane et al., 1996 Nunez et al., 2013 Sapirstein, 2016 Verhoeven et al., 2012) to zoology (e.g., Breuer et al., 2007 Evin et al., 2016 Jaquet, 2006 Munoz‐Munoz et al., 2016 Shrader et al., 2006). Nowadays it is an accurate, precise, and cheap technique (Munoz‐Munoz et al., 2016). Since the beginning of digital photogrammetry, the processing algorithms have continuously improved and the resolution has increased from several millimeters (Faig, 1981 Lichti et al., 2002) to a few micrometers (Gonzáles et al., 2015 Rüther et al., 2012). Photogrammetry reconstructs the shape, color, and texture of the surface of objects from multiple pictures (Kraus, 2007) using a least‐squares algorithm (Evin et al., 2016 Rüther et al., 2012). Surface scanning has been successfully employed in osteology and anthropology (e.g., Hennessy & Stringer, 2002 Motani, 2005 Niven et al., 2009 Sholts et al., 2010 Tocheri et al., 2005 Windhager et al., 2019), medicine (e.g., Da Silveira et al., 2003 Kau et al., 2005 Kovacs et al., 2006 Toma et al., 2009 Yamada et al., 2002) and archaeology (e.g., Counts et al., 2016 Godin et al., 2002 Grosman et al., 2008 Kuzminsky & Gardiner, 2012 Wachowiak & Karas, 2009). Hair, reflective surfaces, sharp edges, small holes, and translucent materials as well as dark or black‐colored materials are also difficult to scan. Shaded areas, undercuts, and narrow structures that are outside the triangulation angle cannot be represented well in the 3D model (Friess, 2012). Most surface scanners utilize the principle of triangulation to estimate a point cloud and to calculate a polygon mesh.

#Arm bones 123d models portable

Many scanners are lightweight, handheld, and portable (Adams et al., 2015). Laser beams produce fewer errors in the surface mesh and are less problematic in daylight however, no texture information is collected (Friess, 2012). Light scanners provide colors and a sufficient resolution to measure distances or to place landmarks on human bones. Surface scanners emit laser or visible light to survey the surface of an object.

#Arm bones 123d models