Donaldson’s School is an A-listed building in Edinburgh built in 1850. It was designed by architect William Henry Playfair.
The building is built round a quadrangle with a Tudor architectural style. It features large corner towers which themselves are made up of four smaller spires.
Queen Victoria opened Donaldson’s in 1851 and allegedly remarked that the building was more impressive than her own palaces.
Following a residential conversion by City & Country, UAV 365 were approached to survey the structure. The primary flight goal was to provide as-built records for the new residents of the Playfair at Donaldson’s.
Aerial Survey Method
The aerial survey was carried out using the DJI Matrice 210 V2 with a Zenmuse X7 sensor equipped with a 24mm lens. To successfully survey a building of this size within a congested area, the UAV 365 team carried out extensive pre-flight engagement and planning. Detailed flight planning ensured that all angles of the building were captured and sufficient image overlap was maintained.
The operation took two days in total and the Matrice 210 was in the air for a total of 5.5 hours. During the first day of flying 90% of the building was captured. This data set was then analysed to provide a final flight plan for the second day of operations. The second day primarily focused on areas that required additional angles to capture their detail.
Horizontal flights were pre-programmed using the latest version of Hammer, a flight control application UAV 365 have been testing. It was not possible to cover all areas of the building using this software so for specific shots or sections that required flying in close proximity to the structure, flight control was handled manually. Hammer released an update after this project completed which would have allowed significantly more automation of the survey. Based on the frequent product updates, the team at Hammer are rapidly improving their software through a tight user feedback loop.
In total 1740 individual images were captured of the building. Ground control points were deployed to ensure the final model was accurately geolocated and future comparisons could be made.
An overflight was also carried out using the DJI Phantom 4 RTK drone prior to the main mission. This provided a supplementary dataset to measure geolocation data against.
Processing the Data
Back in the office the assembled visual data was processed through Reality Capture.
Use of Reality Capture allowed the stunning architecture and detail of the building to be displayed in high resolution. Combining this high detail with high location accuracy allows for detailed inspection on a technical level.
The 3D model provides a feedback loop between the client and UAV 365. Areas of concern can be highlighted and the original visual data located. This enables high resolution inspection of every area on the structure.
Sharing the Model
Tap here to explore the model – we are using the Nira platform to allow exploration of the full size model.
Capturing a building of this complexity presented several challenges. Strongly repeating geometry throughout the building presented an issue for the data processing software. Overhangs and areas of fine detail had to be carefully logged to ensure they were recorded in sufficient detail. The internal courtyard area doubled the number of external surfaces to capture and process.
Due to the vast amount of detail captured in the final model, the output is significantly larger – at 55 gigabytes – than any current online viewer can handle.
The level of detail available can be seen in the video below, which blends real footage with footage from the model.
In addition to the video above, you can explore some still images of the 3D model here: