Visualising Animal Hard Tissues

从最早的时候起，人们就使用坚硬的骨骼组织，如骨头、鹿角、象牙、角、鲸须和玳瑁，作为原材料，创造了从简单的工具到微妙而令人回味的艺术作品的几乎所有东西。加工这些原材料可以极大地改变它们的外观，而腐烂过程可以使它们几乎无法辨认。今天，动物硬组织几乎完全被金属合金和合成塑料所取代，作为人工制品的原材料，野生动物保护方面的考虑使一些硬组织无法获得和不可接受。随着这些原材料的流失，人们对其特征和特性的熟悉程度已经消失，这对那些从事历史和史前文物工作的人以及对非法贩运的CITES保护材料的检测提出了挑战。然而，正确识别这些材料对于理解这些物品的文化意义、保存需求和真实性至关重要。目前正在进行研究，通过对视觉标准和分析技术的整理、评价和验证来完善和发展鉴定规程。这项工作大大提高了我们识别不同种类象牙制品的信心，或者区分真玳瑁和假犀角或塑料制品的信心。使用低倍率显微镜，这可以通过揭示材料结构和降解模式来完成，而不需要采取毁容样品，也不会对物体造成风险。然而，像木材一样，这些是复杂的3D材料，它们的外观和行为完全不同，这取决于它们的工作方式和物体表面的哪些方面。为了正确地解释证据，有必要根据材料的自然结构来理解物体的方向。当这些材料的类似加工标本无法与所研究的对象进行比较时，这尤其困难。即使这些原材料，如犀牛角，是可用的，这将是非法的（和可疑的道德）准备工作标本。使用印刷或网络资源，通过2D图表和照片来传达这些复杂结构的细节，成功在很大程度上依赖于用户以3D方式思考的能力，并且并不总是导致正确的识别。为了克服这些问题，该项目将开发一个基于网络的资源，用于这些动物组织结构的3D可视化。其核心将是每个原材料的完全可旋转的3D逼真图像，其结构的3D图表和3D x射线（CT扫描）显示内部形状和结构。放大后，材料的表面可以在不同的尺度上进行探索，“热点”连接到一系列放大的照片，显示当它在不同的方向上被切割、以不同的方式工作、断裂、老化或退化时所揭示的结构。一旦确定了正确的材料，就可以通过将物体表面显示的特征与模型中指示的特征相匹配，将物体的图像定向到3D模型的框架上。这将有助于了解原材料是如何被利用的，并提供对所用原始组织尺寸的估计，例如为雕塑提供材料所需的象牙的最小尺寸。在在线教程的支持下，这种交互式可视化资源不仅将提高材料识别的准确性，而且将成为研究人员探索这些原材料在所有时期和地理区域的人工制品制造中使用方式的宝贵工具，无论是功能性工具，宗教物品还是精美艺术品。

From earliest times people have used hard skeletal tissues, such as bone, antler, ivory, horn, baleen (whalebone) and tortoiseshell, as raw material to create almost everything from simple tools to subtle and evocative works of art. Working these raw materials can greatly change their appearance and decay processes can render them almost unrecognisable. Today animal hard tissues have almost entirely been replaced as raw material for artefacts by metallic alloys and synthetic plastics, and wildlife conservation concerns have made some unavailable and unacceptable. With the passing of these raw materials, familiarity with their characteristics and properties has been lost, posing a challenge for those who work with historic and prehistoric artefacts, and to the detection of illegally trafficked, CITES protected materials. The correct identification of these materials is, however, fundamental to understanding the cultural significance, preservation needs and authenticity of these objects.Research is already in hand to refine and develop identification protocols through the collation, evaluation and validation of visual criteria and analytical techniques. This work has made great strides in improving our confidence in recognising, for instance, objects made in different species of ivory or in separating real tortoiseshell from fakes in horn or plastic. Using low-power microscopy, this can be done without the need to take disfiguring samples and at no risk to the object, by revealing the materials structure and patterns of degradation. However, like wood, these are complex 3D materials that can look and behave entirely differently depending on how they are worked and which aspects are revealed in the surfaces of an object. To interpret the evidence correctly it is necessary to understand the orientation of the object in terms of the material's natural structure. This is particularly difficult when similarly worked specimens of these materials are not available for comparison with the object being studied. Even if some of these raw materials, such as rhino horn, were available, it would be illegal (and questionable ethically) to prepare worked specimens. Using printed or web resources, illustrated by 2D diagrams and photographs to convey the detail of these complex structures, success largely relies on the ability of the user to think in 3D, and will not always lead to the correct identification. To overcome these problems, this project will develop a web-based resource for the 3D visualisation of the structures of these animal tissues. At its core will be a fully-rotatable 3D photo-realistic image of each raw material, a 3D diagram of its structure and 3D X-rays (CT scans) revealing the internal shape and structure. Zooming-in, the surface of the material can be explored at different scales with 'hot-spots' linking to photographs at a range of magnifications showing the structures revealed when it is cut in different directions, worked in different ways, fractured, aged or degraded. Once the correct material has been identified, it will be possible to orientate images of the object against the framework of the 3D model by matching the features revealed on the surface of an object with those indicated in the model. This will aid understanding of how the raw material was utilised and provide estimates of the size of the original tissue used, such as the minimum dimensions of the elephant tusk required to provide the material for a sculpture. Supported by on-line tutorials, this interactive visualisation resource will not only improve the accuracy of materials identification but will be an invaluable tool for researchers exploring the way that these raw materials have been used in the manufacture of artefacts, whether functional tools, devotional objects or fine art, across all time periods and geographical zones.