Reality Capture plays central role in National Geographic’s Lost Cities with Albert Lin

Author: Duncan M B Lees

A ground-breaking new TV series for National Geographic combines hi-tech science, breath-taking visuals and genuine exploration to bring to life some of the most extraordinary sites of antiquity. Lost Cities with Albert Lin from Blakeway Productions follows the explorer Dr. Albert Yu-Min Lin as he uncovers new insights about forgotten cities and cultures.

High-definition 3D mapping specialists Visualskies were brought in to provide a bespoke 3D scanning service on location and create the spatial data visualisations for the show. Duncan M B Lees, 3D Scanning Specialist, Visualskies explains, “We worked closely with Albert and the Blakeway crew to develop a narrative based upon a scientific approach to the collection of spatial data. The result is a series of ambitious programmes that deliver powerful, emotional stories with our hi-tech imagery.”

To bring the mysteries of the past vividly into focus in the present, Visualskies used Leica Geosystems laser scanning solutions.

Laser scanning: an exciting new tool for archaeology and exploration

Laser scanning technology was crucial to capture and remodel a level of 3D detail otherwise impossible to achieve, to build a picture of how reality would have looked to our ancestors. Speaking about ruins in Akko (Acre) in Israel, Lees explains, “Utilising drones, terrestrial and aerial laser scanners and our custom-built AR software we enabled Albert to step back in time and truly visualise the city as it used to be in Crusader times.”

Visualskies put together a custom combination of scanning equipment, including the Leica ScanStation P50 long range 3D terrestrial laser scanner, the highly portable Leica RTC360 3D laser scanner and Leica Cyclone and 3DReshaper (Cyclone 3DR) point cloud processing software.

Meeting challenging weather conditions and inaccessible terrain

All of the sites chosen to be included in the program posed challenges for the film and survey crew. From 50-degree deserts in Jordan to the high altitude of Machu Picchu, where “processing in tents up in the rarefied atmosphere with only a pair of temperamental generators for power was less than ideal,” says Lees. The equipment used needed to be both portable and durable. The long-range capabilities of the ScanStation P50 meant that the crew could cover large areas and scan inaccessible sites from a place of safety, while still capturing a high level of detail. The laser scanner is quick to set up, can perform at extreme temperature ranges and is tough enough to withstand a jungle trek.

Accessing Ciudad Perdida (literally 'Lost City') in Santa Marta, Colombia, required a lengthy journey involving first planes and helicopters, then hiking, with the team carrying everything they needed themselves. Lees explains, “Our first impression of the extant remains of the Lost City was a spectacular aerial view that underlined just how difficult it was going to be to document the city and the vast landscape around Ciudad Perdida.”

“A startling impact:” Using 3DReshaper to ‘see’ through dense vegetation

One of these difficulties was dense vegetation. Lees explains: “The majority of the Tayrona complex (in Ciudad Perdida) is almost invisible due to the lush tree cover over the whole Sierra Nevada mountain range, so it was going to be almost impossible to document, digitise and visualise the lost remains using solely traditional survey techniques.”

The team used a combination of aerial and terrestrial scanning techniques and 3DReshaper (Cyclone 3DR) in post-processing to achieve their goal. “It is a perfect solution for cleaning, segmenting and filtering point clouds for a number of 3D modelling and inspection deliverables. 3DReshaper provides us with the ability to strip away the tree cover and visualise what lies below; something that has had a startling impact on many of the projects we have undertaken.”

Easing the pressure of tight timescales and ‘one chance’ to get results

Along with geographical constraints, Visualskies needed to survey quickly, to meet a tight travel schedule and tight film production deadlines. “The schedule for the whole Lost Cities series was incredibly compact; with digitally documenting the numerous sites, visualising the remains and filming the whole programme all being undertaken in one relatively short concurrent timescale,” explains Lees.

The equipment used needed to be quick to set-up and easy-to-use, reducing the stress and pressure that the team were under. Both the Scanstation P50 and RTC360 are fast scanners. Using the ScanStation P50 the team were able to capture an entire site at Khirbet al-Darieh, Jordan - and have a 3D model ready to film for broadcast - in just one day.

Lees says that “the RTC360 has been a game changing addition to our 3D reality capture capabilities. We can now collect over twice as much data in any working shift or, more importantly, halve our time capturing data at any location.” The speed of processing software is equally as important. Lees continues, “Cyclone can process huge amounts of terrestrial laser scanning data - hundreds of individual scanner setups resulting in many hundreds of millions of individual points - enabling the registration, manipulation and analysis of the resulting geospatial point cloud dataset with ease.”

“The use of laser scanning and 3D modelling on Lost Cities with Albert Lin was not only fascinating for audiences, but it has also real archaeological value too,” says Lees. For example, on the Pacific island of Pohnpaip, the Visualskies crew scanned an extraordinary collection of over 700 prehistoric motifs carved into a natural basalt terrace. “By creating 3D models of the petroglyphs, we enabled Albert and the crew to clarify the exact form of the fading petroglyphs, to study them in detail and to make comparisons with other ancient carvings from elsewhere in the Pacific.”

Working on the programme has created a new direction for Visualskies, leading them to develop a ground-breaking scouting tool for the TV and film industry. Due for official release in January 2021, VSScout has been designed as a tool-kit to aid productions to explore locations in a radically immersive manner, whilst simultaneously collecting rich geomatic data that can be utilised across departments enabling all crew to access the site remotely.

Lees concludes, “It is our privilege and pleasure to work with exceptional professionals in incredible places around the world, dovetailing our bespoke solutions into the creative process to produce breath-taking results for all to see.”