Lehman Caves in the Great Basin National Park (Nevada/USA)

By Admin
September 9, 2020
Interiors and architecture

In February 2020, the team around speleologist Blase LaSala was commissioned to digitise Lehman Caves in eastern Nevada/USA and make them virtually accessible. As in many museums around the world, visitor access had to be suspended due to the Covid-19 pandemic.

The Lehman Caves, named after their discoverer Absalom Lehman, are located in eastern Nevada/USA, between Las Vegas and Salt Lake City, and have been protected as a natural monument since 1922 and as part of the "Great Basin" National Park since 1986. The underground dripstone cave stretches over a length of about 3 kilometres, and lies at a depth of 25 to 60 metres. Particularly interesting about this cave is the very diverse fauna, which includes rare insects and spiders to bats and other mammals.

In order to remain "visitable" for visitors during the Covid-19-related closure, the decision was made early on to digitise the cave in full 3D and publish it on the internet. In February 2020, Blase LaSala and his team started the work, using a LiDAR scanner from the manufacturer Faro for the 3D acquisition and the automatic panorama system piXplorer 5oo for the creation of the high-quality textures.

Bubble LaSala and Eric Weaver prepare the LiDAR scan — Blase LaSala and Eric Weaver prepare the LiDAR scan (Image: NPS/G. Baker)

The first step is to carry out the laser scan, — The laser scan is carried out first, (Image: B. LaSala)

and then the laser scanner on the tripod was replaced by the panorama system: — and then the laser scanner on the tripod was replaced by the panorama system. (Image: B. LaSala)

In order to be able to combine texture and laser scan congruently with this method, it is necessary to compensate for the difference in height of the tilt axis of both systems on the tripod with the help of a special adapter. What sounds complicated at first is easy to realise in practice, as the manufacturer CLAUSS offers corresponding adapters.

In total, more than 250 viewpoints were recorded in this way within 2 weeks. In order to create an overall model from the individual viewpoints, they have to be linked together:

Linking the scenes in the Unreal Engine (Epic Games) — Linking the scenes in the Unreal Engine/Epic Games (Image: B. LaSala)

The result is impressive: