CloudCompare

  • 文章类型: Journal Article
    对象咬伤留下的痕迹(bitemark)代表了明确的特征,有助于确定犯罪的可能肇事者。迄今为止,对bitemarks的分析主要基于摄影发现的直接视觉以及与假设负责人的牙齿的视觉比较。然而,bitemark还保留了3D扫描仪可检测的三维特性。在这项试点研究中,一种创新的bitemark分析方法,利用三维扫描仪和一些软件,将被介绍,能够定量比较bitemarks及其相应的人类牙列。为此,使用10个成年受试者的10个完整的石膏模型(人类牙列)在牙科蜡上制作20个实验性bitemarks。用iTero®3D扫描仪单独扫描所有材料,并用MeshMixer软件重新加工。还进行了特征的视觉分析和使用CloudCompare软件的计算机化分析。研究表明,比较人类牙列以及重合和非重合位标记所获得的点的分布曲线具有不同的趋势。目前的结果支持口内3D扫描仪允许快速记录和保留bitemarks的三维特征,它允许进行计算机化分析。
    The marks left by the bite of a subject (bitemark) represent an unequivocal character, being useful in identifying the possible perpetrator of a crime. To date, the analysis of bitemarks is mainly based on the direct vision of photographic finds and on the visual comparison with the teeth of the hypothetically responsible person. However, the bitemark also retains three-dimensional characteristics detectable with a 3D scanner. In this pilot study, an innovative method of bitemark analysis, utilizing a three-dimensional scanner and some software, will be introduced, enabling a quantitative comparison of bitemarks and their corresponding human dentitions. For this purpose, 10 complete plaster models (human dentitions) of 10 adult subjects were used to make 20 experimental bitemarks on dentistry wax. All materials were individually scanned with the iTero® 3D scanner and reworked with MeshMixer software. A visual analysis of the characteristics and a computerized analysis with the CloudCompare software were also performed. Study showed a different trend of the distribution curves of the points which were obtained comparing the human dentition and coincident and non-coincident bitemarks. Current results support that the intraoral 3D scanner allows the fast record and the preservation of the three-dimensional characteristics of the bitemarks, and it allows computerized analyses to be carried out.
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  • 文章类型: Journal Article
    目的:无人机图像数据集可用于野外测量和图像数据收集,可用于分析。使用当前的无人机地图软件,有用的3D对象重建是可能的。这项研究的目的是学习3D数据集构建过程的树木与开源软件和他们的使用。因此,我们研究了用于3D数据集构建的工具,尤其是在农业领域。由于不断发展的开源社区,我们展示了我们的棕榈和椰子数据集与开源数据集的案例研究。
    结果:实现点云数据集的方法基于以下工具:OpenDroneMap,CloudCompare,Open3D因此,提取了40棵棕榈树和40棵椰子树点云。在体积估计和图形分析领域提供了用法的示例。
    OBJECTIVE: Drone image data set can be utilized for field surveying and image data collection which can be useful for analytics. With the current drone mapping software, useful 3D object reconstruction is possible. This research aims to learn the 3D data set construction process for trees with open-source software along with their usage. Thus, we research the tools used for 3D data set construction, especially in the agriculture field. Due to the growing open-source community, we demonstrate the case study of our palm and coconut data sets against the open-source ones.
    RESULTS: The methodology for achieving the point cloud data set was based on the tools: OpenDroneMap, CloudCompare, and Open3D. As a result, 40 palm trees and 40 coconut tree point clouds were extracted. Examples of the usages are provided in the area of volume estimation and graph analytics.
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  • 文章类型: Journal Article
    海平面上升,以及其他生物和人为因素,在大西洋海岸线沿线的许多重要地点,侵蚀率增加。GaltFish项目实施了一系列应急措施,以在其中一些网站进一步退化或完全消失之前进行记录。此过程涉及在一段时间内对某些受到威胁的站点进行详细的摄影测量记录。该项目选定的地点之一是Sobreira(Vigo,加利西亚):一家罗马的鱼盐厂,在1980年代被建筑活动部分摧毁,其遗骸受到海洋侵蚀和人类活动的威胁。为了研究该网站,创建了两个摄影测量模型,以检查侵蚀过程在一年中的影响。结果表明,摄影测量是记录和分析侵蚀问题的有效工具。编译的数据有助于在工厂中设计额外的操作,进行了救援挖掘,以记录并帮助保护现场免受进一步损坏。本文介绍了该项目的结果,以及用于生成模型的方法,生成的数据及其分析。有人认为,这种方法可以用来收集和分析其他网站的数据,这些数据可以为政治/行政决策过程提供信息,这些过程涉及未来受到威胁的考古遗址的管理和保护。
    Rising sea levels, along with other biological and human factors, have increased erosion rates at a number of important sites located along the Atlantic coastline. Project GaltFish implemented a series of contingency measures to record some of these sites before they degraded further or totally disappeared. This process involved detailed photogrammetric recording of some of the sites under threat over a set period of time. One of the sites selected for this project was Sobreira (Vigo, Galicia): a Roman fish-salting factory which was partially destroyed by building activity in the 1980s and the remains of which are under threat from marine erosion and human action. In order to study the site, two photogrammetric models were created to examine the effect of erosive processes across the course of one year. The results illustrate that photogrammetry is an efficient tool for recording and analysing the issue of erosion. The data compiled helped in designing additional action in the factory, which was subject to a rescue excavation to record and help protect the site from further damage. This paper presents the results of this project, as well as the methodology used to produce the models, the data generated and their analysis. It is argued that the methodology can be used to collect and analyse data from other sites, and that this data could inform the political/administrative decision-making processes which concern the future management and preservation of archaeological sites under threat.
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  • 文章类型: Journal Article
    Using the best-fit ellipse method, single bullet impacts in thin sheet metal were assessed to investigate the accuracy of impact angle estimation. When a bullet passes through a metal panel, the yielding nature of metal causes changes to the metal surface and the resultant hole. This deformation of the metal complicates the assessment of single impacts using the ellipse method. Determining the correct impact angle may not be obvious and results in considerable errors between the known and calculated angle. To determine if the calculated angle varies in any particular way to the known angle, impacts were created on metal panels using six different types of 9 mm ammunition and seven angles from 90° to 14°. Impact angles, determined using the ellipse method, were compared with known firing angles and the error pattern assessed. The results show an error pattern with a significant quadratic relationship for three ammunition types, with the error pattern for the remaining three ammunitions not explained by a quadratic formula and requiring further study. Results suggest that single bullet impacts for a given type of ammunition with a quadratic error pattern, can be assessed with accuracy due to a more consistent behavior. This characteristic pattern of error requires further study but is a promising step for determining an accurate impact angle and bullet path from a single impact point in a metal surface.
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  • 文章类型: Journal Article
    Nasal tip mechanical stability is important for functional and cosmetic nasal airway surgery. Palpation of the nasal tip provides information on tip strength to the surgeon, though it is a purely subjective assessment. Providing a means to simulate nasal tip deformation with a validated model can offer a more objective approach in understanding the mechanics and nuances of the nasal tip support and eventual nasal mechanics as a whole. Herein we present validation of a finite element (FE) model of the nose using physical measurements recorded using an ABS plastic-silicone nasal phantom. Three-dimensional photogrammetry was used to capture the geometry of the phantom at rest and while under steady state load. The silicone used to make the phantom was mechanically tested and characterized using a linear elastic constitutive model. Surface point clouds of the silicone and FE model were compared for both the loaded and unloaded state. The average Hausdorff distance between actual measurements and FE simulations across the nose were 0.39 ± 1.04 mm and deviated up to 2 mm at the outermost boundaries of the model. FE simulation and measurements were in near complete agreement in the immediate vicinity of the nasal tip with millimeter accuracy. We have demonstrated validation of a two-component nasal FE model, which could be used to model more complex modes of deformation where direct measurement may be challenging. This is the first step in developing a nasal model to simulate nasal mechanics and ultimately the interaction between geometry and airflow.
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