Transforming ruins to 3D models

作者：Reka Vasszi

Heliopolis, the City of the Sun was inscribed in 1984 as an UNESCO World Heritage site. This ancient Roman city, today called Baalbek, in the Beqaa Valley in Lebanon has a complex of temples that is an outstanding example of ancient Roman architecture. The Temple of Bacchus, in the sanctuary complex of Baalbek, is among the largest, best preserved and most impressive of its kind.

Todigitally document并保留Bacchus神庙的威严，以后，黎巴嫩国际大学的测量工程系的硕士学生captured the temple in 3D.

“We used a new automatic digital 3D terrestrial laser scanning technique to create a 3D model of the Temple of Bacchus. Using theLeica ScanStation P30enabled us to effectively and quickly capture the temple and develop 3D models that can be used for renovation and Virtual Reality (VR) applications,” said Professor Mohammad Abboud from the Lebanese International University.

Identifying layers of history

The Temple of Bacchus, built between 150 to 200 A.D, is the architectural manifestation of the myths and legends surrounding the god of wine, joy, drama and fertility. The Roman God Bacchus was the personification of the blessings of nature, which is gorgeously sculptured on the walls of the ancient temple.

From the 12th to 14th century, the sanctuary complex, including the Temple of Bacchus, was combined and converted into a large castle that became part of Baalbek's medieval fortification. Although subsequent layers of building helped to preserve the antique architecture, distinguishing the stages of this built-environment is a challenge.Archaeologists conduct a complex analysis with modern technology to reconstruct the ancient cityand identify the different historical layers and materials that make up the ancient Roman settlement under the later medieval additions.

尽管古城不断重建，但百年来，巴克斯神庙仍遭受了盗窃，战争和地震的困扰。1759年的地震极大地破坏了圣殿的结构。由于古罗马城市位于容易发生地震的地区，因此重要的是要监视结构并确定可能的运动，以确保游客的安全并保存圣殿。

Creating digital databases for heritage

Laser scanning conducted by surveying engineering students at Lebanese International University proved to be an accurate and effective solution to collect precise data in a limited amount of time and allowed researchers to present archaeology to the public in a unique way—through 3D models and interactive digital applications.

团队使用Leica ScanStation P30. The engineering students then processed the data in the office with LeicaCyclone注册360 3D点云处理软件，以注册并清洁提取表面网格的数据。点云提供了有价值的度量数据，以生成Bacchus庙的详细3D模型。

除了laser scanning, to collect more detailed information,aerial photogrammetry被用来捕获巴克斯神庙及其周围环境的全景照片。

在几何分析，地形建模，摄影测量和3D激光扫描的帮助下，考古学家和建筑研究人员的传统研究方法补充了精确的数字信息。

Comparing traditional and modern technology

Traditional methods, such as GPS devices are more time-consuming and do not capture information in 3D. Traditional 2D drawings are limited in describing exact locations of geometries in a 3D space, and often present the ideal of a space, more so than the reality. Total stations are reliable and capable of collecting 3D data, however, lack the density of points to support 3D visualisation.

Reconstruction of archaeological sites, however, requires the density of data that laser scanning can provide.3D data documentation can leverage traditional survey techniquesto ensure data accuracy and accurate global positioning. This data lends itself to Building Information Modelling (BIM) and other visualisation techniques tocreate a complex digital database, which serves as a base for future restoration or reconstruction如果需要，巴克斯神庙

3D scanning the past for the future

Heritage preservation is a continuous process, thatincludes documentation, analysis, monitoring, restoration and protection. Our cultural heritage treasures, like the Temple of Bacchus, are fragile and vulnerable to environmental and human hazards. Digitising these majestic examples of the built environment can be used to preserve the original site as it exists today and createa digital record of the site that can be accessed long into the future.