文物三维数字化设计及其实验方法研究

文化遗产的数字化设计为文化遗产的保护、传承和利用提供了新的方法。针对文化遗产的数字化设计理论和方法,研究了文化遗产的三维数字化设计关键技术,构建了基于计算机辅助的三维扫描文物数字化重建方法,提出二维图像标定的三维网格纹理映射思路。通过商晚期出土的青铜牛尊文物三维数字化实验,完整地构建了文物数字化设计流程框架,并对文物数字化设计理论和方法进行验证。     

Variability and sampling strategy of cave wall concretion: Case study of the moonmilk found in Leye Cave (Dordogne)

Cave Art is a fragile testimony of past human societies and the development of modern behaviours. In limestone caves, moonmilk commonly endanger the artworks. It is a calcite deposit with a large variability of chemical composition and morphological structures and it hosts numerous microbial communities. The possibility to characterize this deposit in the field would aid in a better understanding of cave behaviour and allow the setting up of proper conservation measures. The present study analyses the variability of a moonmilk strip of metric size in Leye Cave in the Vézère Valley (Dordogne, France). The cave was not ornate and was selected as a laboratory cave in which in‐situ observations and micro‐sampling could be carried out, before they were performed in cavities hosting parietal artworks. Scanning electron microscope (SEM) observations of 24 samples allowed, for the first time, an investigation of the variability of moonmilk deposits over the same wall of a few metres dimension. The observations highlighted the low variability of the moonmilk at the microscopic scale when regarding the chemical composition and morphological structures, despite significant macroscopic diversity, thus providing insights into how to optimize the sampling strategy of moonmilk in ornate caves.     

Rapid On‐site Topographic Mapping with a Handheld Laser Range Finder for a Geoarchaeological Survey in Syria

A digital elevation model and a topographic map of an archaeological site in Syria were created from a field topographic survey with a handheld laser range finder and data post‐processing using a notebook personal computer with Geographical Information System software. The method enabled rapid on‐site topographical mapping even under technical and political restrictions in the country. In an area of about 1 km², coordinates of random points on the land surface were measured, and a DEM with a 10 m interval grid was generated from the point cloud using Kriging interpolation. The DEM enables various topographic representations to be constructed, such as contour lines, cross sections and slope distribution maps. The DEM‐derived contour lines with a 1 m interval were combined with vector data showing roads and buildings to provide a topographic map. Topographic cross sections created from the DEM generally agree with sections surveyed with a hand level and a measurement tape. The obtained DEM and map are useful for preliminary field research.     

Provenance of Early Bronze Age metal artefacts in Western Switzerland using elemental and lead isotopic compositions and their possible relation with copper minerals of the nearby Valais

Ten Early Bronze Age (BzA1, 2200–2000 BC) copper artefacts from the central Valais region from Switzerland were studied for their elemental composition and lead isotope ratios. In order to answer the archaeological question of a local copper supply, a database for copper minerals across the Valais (Switzerland) has been established. This database contains 69 data on lead isotope ratios as well as additional information on the minerals and geochemical associations for copper minerals from 38 locations in the Valais. Comparisons of the artefacts were also made with data pertaining to minerals from various deposits from Europe and Anatolia taken from the literature. The provenance of the materials is very diverse. Some of the data are compatible with the data from the copper mineral deposits of the Valais region. Moreover, three copper lunulae were identified as possibly Tuscan, which suggests contacts between Italy and the Valais region. This pattern also establishes a multiplicity of provenances for the metal and cultural influences in the Alpine environment of the Rhone Valley of Switzerland at the beginning of the Early Bronze Age.     

Using airborne small-footprint laser scanner data for detection of cultural remains in forests: an experimental study of the effects of pulse density and DTM smoothing

Cultural remains are laborious to register by means of field surveys. Thus, in recent years several trials using remote sensing data to detect cultural remains have been carried out. The most promising remote sensing technique for such purposes is airborne laser scanning (ALS) from which digital terrain models (DTM) that enable visual interpretations of anomalies on the ground are generated. Although it has been documented previously that ALS is a powerful data source for detection of cultural remains, it has not yet been carried out studies that focus on the effects of the point density of the ALS data and properties of the subsequent generation of the DTM on the detection success of cultural remains. Thus, this study aimed at analyzing these effects by letting four experienced archeologists interpret DTMs generated from ALS data with point densities of 1 p m⁻², 5 p m⁻², and 10 p m⁻², each with three different levels of DTM smoothing. The experiment was conducted according to a randomized complete block design and the analyses were carried out using analysis of variance. The results showed that there was a significant improvement in the detection success when the point density was increased from 1 p m⁻² to 5 p m⁻². There were also some improvements when increasing the point density further to 10 p m⁻², but they were less pronounced. Furthermore, the results showed that the DTM smoothing did not have any significant effect on the detection success.     

Using 3D scanning in the investigation of Upper Palaeolithic engravings: first results of a pilot study

This paper deals with the reinvestigation of selected engravings on slate plaquettes from the Late Upper Palaeolithic site of Gönnersdorf, Germany, by applying new 3D scanning methods for the first time. The aim of this method is to obtain further information about stylistic aspects of the depictions as well as to identify an inner chronology and interrelationship of the lines. In addition new options of 3D photography are tested as a further visual support of investigation and documentation. Previously analyses were subjective whereas the new interpretation uses impartial metric methods. In the future the more objective results will allow the comparison of engravings and their details, with the aim of discerning different artists as well as obtaining a better understanding of the art of former hunter- gatherer societies.     

基于高精度三维模型的大型石窟类文物等比例复制

文物复制是文化遗产(尤其是超大型不可移动文物)保护、传承和发展的重要基础,三维激光扫描、3D打印等新兴技术的发展为文物复制提供了新的思路。本研究以云冈第18窟为研究对象,首次探索并建立了基于高精度三维模型的超大型文物等比例高保真复制技术体系,主要包括:高保真数据获取、三维重建、复制模型分块、打印与安装、高保真涂料喷绘。该方法已应用在云冈第18窟等大型石窟类文物的等比例高保真复制工程。结果表明,本方法能够实现大型石窟类文物的高保真等比例复制,复制成果满足可移动的实际需求。该方法可为类似的文化遗产保护工作提供一定的借鉴和指导。     

汉阳陵东阙门出土黑色颜料的科学分析

为了科学分析汉阳陵东阙门西壁黑色颜料的组成和进一步探讨汉代皇陵颜料的使用状况,采用超景深显微观察、扫描电镜能谱(SEM-EDS)以及面扫描技术、X射线衍射(XRD)等测试方法,结合文献资料进行了科学分析鉴定与深入探讨。结果表明该黑色成分是氧化铜,应是原先含铜的蓝绿色颜料经过火烧氧化后所造成,属后呈现色彩。这一结果为后续彩绘类文物颜料鉴定提供科学思维,即不仅使用现代分析测试手段分析鉴定当前状态下的颜料种类,还应结合文物所处的环境变化,科学系统地指明其色彩呈现形式。另外,实验中使用的扫描电镜能谱面扫描技术可清楚确认颜料颗粒的分布情况,在微观分析颜料颗粒方面具有不可比拟的优越性。     

三维激光扫描技术在岩土文物保护中的应用

三维激光扫描是近年来飞跃发展的一项高新测绘与信息技术,在文物保护中发挥了重要作用介绍了三维激光扫描技术的主要特点,从岩土文物保护需求出发,结合实际文物保护工程,重点介绍了三维激光扫描技术在文物信息留存、虚拟修复、监测等方面的应用,最后指出三维扫描技术在岩土文物保护中的心用与发展须与保护需求紧密结合,而硬软件的改进完善及相关技术的集成心用亦是重要研究方向。     

三维激光扫描在文物考古中应用述评

对文物和遗址遗存进行精确描述和测绘一直是文物保护和考古发掘工作中的一个重要内容。相较于传统测绘方法,三维激光扫描具有快速、准确、无需接触文物表面等优势,已被广泛采用于文物保护和考古发掘工作中。本文对三维激光扫描的原理和工作流程进行简要介绍,并对其近期在文物保护和考古工作中的应用情况做出综述和评论。