GPS World

Tag: historic

  • 3D scanning experts digitize Japan’s historic Odawara Castle

    3D scanning experts digitize Japan’s historic Odawara Castle

    Using Artec Jet, Artec Ray II and Artec Leo, 3D scanning experts have digitized Japan’s historic Odawara Castle for heritage preservation and potential future restoration projects

    Challenge: Capturing a massive heritage site, including every detail from courtyards and buildings down to a drawbridge and individual rivets on castle gates. 

    Solution: Artec Jet, Artec Ray II, Artec Leo, Artec Twins 

    Result: A single, interconnected point cloud covering the entire facility — scanned mostly with Artec Jet, but with areas of interest captured more accurately using Artec Ray II & Leo. The resulting high-density dataset can be explored in 3D, making it suitable for virtual museum tours, or continuous monitoring to ensure Japan’s famed Odawara Castle stands the test of time. 

    Why Artec 3D? The highly maneuverable Artec Jet can be attached to a backpack and simply walked through an environment. Entire scenes can be captured from ground level in minutes, including tall structures from a range of up to 300 meters. Artec Ray II and Leo deliver higher accuracy for applications like long-term monitoring, damage assessment, and restoration. 

    Odawara Castle: A gateway into Japan’s past

    Odawara Castle was built more than 500 years ago, with fortifications first erected during the Kamakura period — a time famous for the emergence of the Samurai and Japan’s first Shogun. 

    The site’s illustrious walls are steeped in history. Situated on a hill and surrounded by a moat, the castle has strong fortifications, so it was coveted and fought over for generations. Three sieges of Odawara took place from 1561-90 and the structure changed hands (and shape) multiple times over the next century as different leaders left their stamp on the property. 

    At times, the legacy of Odawara Castle has been difficult to protect. The entire site was shaken to its foundations by multiple earthquakes from 1703-1853 and the Meiji government of the late 19th century ordered that all feudal structures be destroyed, so it was mostly torn down. 

    In 1938, what remained of Odawara Castle was made a heritage site and slowly rebuilt. But over the years, it has remained a delicate piece of history in need of ongoing renovation. With this in mind, the Artec 3D support team — in Japan for a recent trade mission — opted to digitize the entire structure for future generations to enjoy using Artec Jet, Artec Ray II and Artec Leo. 

    Artec Jet (dark blue), Artec Ray II (light blue), and Artec Leo (grey) point cloud data fused together for high detail on every scale. (Credit: Artec 3D).
    Artec Jet (dark blue), Artec Ray II (light blue), and Artec Leo (grey) point-cloud data fused together for high detail on every scale. (Credit: Artec 3D).

    Capturing an entire castle in minutes 

    When they arrived at the castle, engineers immediately understood the scale of the challenge  they were embarking on. Once one of medieval Japan’s largest fortifications, the site’s outer defensive perimeter is a whopping nine kilometers long. Odawara Castle is also a national landmark that’s open to visitors, so they didn’t have the facility all to themselves either.

    This meant that speed and subtlety were critical. It would’ve been entirely possible to capture the site with a lidar, tripod-mounted Ray II, by positioning it around different areas of the fort. But this would take a prohibitive amount of time — especially when you consider that double scans are required to remove moving objects. Using Artec Jet was a lot more straightforward. 

    Attaching the device to a backpack meant the castle could be scanned on foot. Walking the site, almost as if they were a tourist, was enough to capture the entire scene. Artec Jet’s remote app gave real-time feedback on scan progress, so the team didn’t leave any detail uncaptured — and compared to capture with shorter-range scanners, the time savings were enormous. 

    “Artec Jet scans in a linear fashion. If it takes you two minutes to walk, it’ll take two minutes to scan — the complexity of the scene has little bearing,” explains Artec 3D scanning expert Keynan Tenenboim. “In the same time it took for Leo to scan 2-3 walls, Ray II scanned a building, and Jet digitized an entire castle. Adding in Ray II & Leo was great for areas with accessibility issues — and capturing higher detail around the walls, gate, and courtyard.” 

    A Trio of Scanners for the Task

    Natural environments like trees, rivers, and larger connecting spaces often offer valuable site context, but don’t need to be captured with high accuracy. Artec Jet was perfect for picking up this sort of background information, generating a continuous point cloud, and connecting the site’s more interesting features: historic walls, ornate roofs, and courtyards around the castle. 

    Jet’s 300-meter range meant there was no need for ladders or scaffolding. The inner structure was captured from ground level without other visitors even noticing. Unlike Ray II, which scans from static viewpoints, Jet could also be maneuvered into difficult-to-reach areas. Both scanners are less accurate than Leo — but that’s why it’s best to combine datasets, for peak results. 

    In this case, Ray II was deployed to scan the inner courtyard and gate, with Leo being used to pick up smaller details like the confined area behind the entrance. Handheld 3D scanning was also perfect for capturing a nearby medieval wall. As you can see from the scan below, fine details like tile patterns, lettering, and the wall’s internals were all captured in a single sweep. 

    “This was the perfect project for demonstrating the benefits of all three scanners,” said Tenenboim. “The main castle wouldn’t be a good fit for Leo and it didn’t really fit Ray II. There was no good vantage point where we could see the facade from 100 meters away. Thanks to Jet’s range, we were able to scan from a ground level. Okay, we could’ve improved roof capture by flying Jet on a drone — but this would require more site preparation.” 

    Fine details of an exterior wall captured just outside the castle with Artec Leo. (Credit: Artec 3D)
    Fine details of an exterior wall captured just outside the castle with Artec Leo. (Credit: Artec 3D)

    Heritage preservation with end-use potential 

    Once engineers had finished scanning, they sent data back to Artec’s Luxembourg HQ via cloud sharing for processing in Artec Twins. Specifically designed to handle large datasets, Artec Twins software allows Artec Jet, Ray & Leo scans to be merged — either into a unified point cloud, or a 3D mesh that can be measured and exported to industry platforms like Autodesk Revit. 

    In terms of applications, the resulting 3D point cloud would be perfect for building a virtual museum tour that allows visitors to virtually explore Odawara Castle. Regular data capture sessions would also allow site operators to monitor conditions over time. If a building’s traditional rooftop began to sag, for example, it’d be possible to carry out rapid repairs.

    Deployable in seven modes: by-hand, backpack, pole, cage, robot, vehicle, or drone, Artec Jet adapts to any environment, allowing users to replace complicated multi-tool workflows. Clearly, Artec’s Odawara Castle scan is just the beginning, there are many more sites left to explore. 

    See the captured dataset from this project here. 

  • Harnessing scan-to-BIM technology on historic sites

    Attucks School in Kansas City.
    Attucks School in Kansas City. (Image: GeoSLAM)

    When it comes to renovating a building, unforeseen structural problems or lack of knowledge about the materials used can result in costly delays. Detailed site surveys help to highlight these issues before work begins — and digital technology is playing an increasingly important role in identifying them.

    The GeoSLAM ZEB REVO. (Image: GeoSLAM)
    The GeoSLAM ZEB-REVO. (Image: GeoSLAM)

    A project undertaken at a 112-year-old school highlights the advantages of using 3D mobile indoor mapping for rapid and simple site surveys.

    “The beauty of scanning an historic building is that you find yourself delving into the stories behind its life,” said Stuart Cadge, sales and marketing coordinator at GeoSLAM. “As you peel back the layers you discover how the building has been used and altered over many decades of use.”

    This was certainly the case at the Attucks school in Kansas City, Cadge said. The distinctive red-brick building was designed by local architect Charles A. Smith and built in 1905. It is known for its colonial revival influences and also played a key role in the educational history of the African-American community.

    Two decades later, the school was suffering from over-crowding, and Smith was asked to extend it with a two-storey wing that connected to the east façade of the building. While the 1905 building had been symmetrical, the extension changed the floor plans considerably. Nevertheless, Smith delivered a sympathetic design that incorporated some of the original architectural details, ensuring the new wing was in keeping with the building’s aesthetic.

    While details of the school’s building history are available on national and state registers, it would not have been possible to uncover problems in its structural condition without an accurate survey.

    A Unique Challenge

    Redeveloping and retrofitting a building like Attucks requires careful planning to uncover any existing conditions in its infrastructure. Civil engineering firm BHC RHODES was tasked with providing a 3D Revit building information model (BIM) of the building. The firm decided to use lidar 3D mobile mapping technology provided by GeoSLAM to achieve this.

    The extremely rapid and efficient workflow of the GeoSLAM solution meant that possible setbacks in the project, caused by weakness in the structure, could be identified in advance, helping to speed up delivery time and reduce the overall project spend.

    At Attucks, there were visible signs of deterioration to the wooden flooring, as well as concerns about ceiling collapses and air quality — specifically, asbestos.

    The Value of Technology

    “The process of mapping a historic building can expose site personnel to a number of risks, so BHC RHODES wanted to ensure they spent as little time on-site as possible,” Cadge explained.

    As well as entering the Attucks building, personnel were required to move across the site safely, climb stairs and go into places that a trolley scanner could not.

    On this basis, the firm chose the GeoSLAM ZEB-REVO, a handheld, lightweight, mobile mapping scanner, which employs 3D Simultaneous Localization And Mapping (SLAM) technology. In this case, it was seen as a much more time- and cost-effective alternative to terrestrial, static or trolley-based systems.

    The complete 3D scan of the building comprises four separate scans and over 160 million data points. (Image: GeoSLAM)
    The complete 3D scan of the building comprises four separate scans and over 160 million data points. (Image: GeoSLAM)

    “The ZEB-REVO is an incredibly useful tool for indoor mobile mapping, particularly in buildings with multiple storeys,” Cadge said. “It enables users to simply ‘walk and scan’ the building, in order to generate building footprints, 2D plans, area measurements for real estate and facility management, 3D BIM models — the list goes on.”

    In the case of Attucks, just four-and-and-half hours were needed to scan the whole building, with the ZEB-REVO recording more than 43,000 measurement points per second. This was helped by the fact that operation of the device requires minimal staff training.

    Results

    Data from the ZEB-REVO and a trolley-based scanner were registered with Cyclone 9.1.4 to a common coordinate system before being exported to Autodesk ReCap as a .pts file format. From this, data was divided into 10-GB files to be used in ReCap and Revit 2014, where a level 200 BIM model was generated. The smooth and hassle-free workflow resulted in the entire building model being completed two weeks earlier than predicted.

    The Jazz District Redevelopment Corporation (JDRC) in Kansas City has plans to transform Attucks into a new community performing arts facility, with office space, paying tribute to its African-American history. By supplying the JDRC with the geospatial data, the organization was better able to understand the structural condition of the building and consider how the space could be used.

    The 3D point data was used to build a level 200 BIM model in Recap and Revit 2014. (Image: GeoSLAM)
    The 3D point data was used to build a level 200 BIM model in Recap and Revit 2014. (Image: GeoSLAM)

    The development will form an integral part of the 18th and Vine historic district in Kansas City, known as the Jazz District. The area is recognized as one of the cradles of jazz music in the 1920s and 1940s, and a historic hub of African-American businesses.

    To secure approval on the plans for Attucks, JDRC must produce detailed drawings that show what materials will be used, as well as full dimension drawings, floor plans, site drawings and elevations. In addition, it must provide details, both graphically and in written form, on what parts of the building will remain and what renovation techniques will be used.

    All this might present a number of challenges, but the scans produced by GeoSLAM’s ZEB-REVO show that the existing buildings are of exceptional quality. When the project does proceed, it will be able to do so quickly and efficiently thanks in part to the speed, simplicity and ease of use of the ZEB-REVO.