Rescue Mission: Using reality capture to plan the re-development of a former convent

Author: André Azevedo

在葡萄牙布拉加（Braga）的Carmo Church旁边，坐在1653年成立的前Carmelite修道院。

To decide on the best way to sympathetically develop the complex site, which includes vaults, attics, and water features, Fortera asked civil engineering companyBuildgestto carry out a complete geometric survey. To capture the data needed to build a BIM model, André Azevedo, technical manager at Buildgest used a Leica Geosystems 3D laser scanning solution.

Visualising the environment as it is in 3D

该修道院的内部和外部由多个建筑物，水平和室外空间组成。在任命BuildEmp之前，Fortera已经委托进行了2D调查。不幸的是，这没有足够的细节使他们自信地进入开发的设计阶段。Azevedo解释说：“经典的2D调查有一些缺陷，因此我们提出了激光扫描调查和建筑物的准确建筑模型。该建筑信息模型（BIM）将帮助客户的建筑师团队研究不同的干预场景。”

Faster scanning in the field with a streamlined reality capture solution

With a potential construction area of 5,000 square metres, complex geometry and a six-week deadline, Buildgest needed to carry out their fieldwork quickly. If they took too long, their modelling team would not have enough time to complete the work.

Azevedo已经是Leica Geosystems用户选择的Leica BLK360imaging laser scanner,Cyclone REGISTER 360,Cyclone FIELD 360, 3DReshaper (旋风3dr) andJetStream Viewersoftware elements.

“We needed equipment that can produce interior scanning quickly and accurately. The scanner is small and light compared to other equipment and that facilitated transportation to difficult zones of the buildings like attics and caves. The workflow between the products and software is smooth and quick. For example, Cyclone FIELD 360 pre-registers the scans automatically. That gives us faster scanning in the field,” explains Azevedo.

600 scans in seven days

Azevedo and his team used two BLK360 scanners in parallel for seven days to scan the convent buildings. The BLK360 - the smallest and lightest imaging laser scanner of its kind - captured the site with full-colour panoramic images overlaid on a high-accuracy point cloud. To make sure that the overall point cloud was accurate, Buildgest established a survey control network with laser scan targets around the building and in the interior.

A total of 600 detailed scans were taken. To improve efficiency, Azevedo used the Cyclone FIELD 360 mobile-device app to pre-register the point cloud while still on site. In his words, “Pre-registration of the collected information in the field saved time in post-processing tasks.”

Easy synchronisation, interoperability and processing

Back in the office, the Buildgest team used Cyclone REGISTER 360 to clean and register the scans, creating a unified point cloud. Azevedo says, “The synchronisation between Cyclone FIELD and Cyclone REGISTER is good and makes it easy to use.”

处理包括给出一些形状更多的定义。Azevedo解释说：“观赏细节，例如在内部露台上的中央喷泉是在3dreshaper的帮助下建模的。”然后，在五个星期的时间内，由两个建模者组成的团队进一步处理数据，为客户创建完整的体系结构BIM模型。Azevedo将准确扫描数据的价值解释为对此过程的价值，“对修道院的现有保管库进行建模是具有挑战性的，使用点云帮助我们完全了解了这些元素的几何形状。”

“It's helpful to review the model with the photographic record”

When the geometric survey was complete, Buildgest presented their findings to Fortera. As well as delivering the BIM model, and an LGS file of the data, Buildgest used a Cyclone Publisher Pro and JetStream Viewer to show the client how to explore and move the point cloud. They see this as the best way to communicate the results.

“We always recommend the JetStream Viewer to our clients, because it's more specific and helpful to review the model with the photographic record. Using the viewer, the client was able to see the 360 images that were captured in the scanning process. Besides, it gives them the option to navigate through the point cloud with a simple intuitive tool,” Explains Azevedo. JetStream Viewer Portable is a free, no-install version designed for easy visualisation, to let those without survey training experience point cloud data.

Buildgest was able to complete the project quickly without compromising on quality. Pedro Ferreira, chief engineer at Fortera, says, “Fortera was truly satisfied with the amount and quality of information that was delivered.” Now it’s over to the developer’s architects to plan a reinvention of the buildings, adding another chapter to the convent’s 350-year story.