Laser scanning, video imagery and robotics are being combined in a development project that can produce dimensioned and textured models of real interiors, accurate to 40mm - enough for many surveying applications.
The objective of RESOLV - Reconstruction using Scanned Laser & Video - is to build a spatial model of the surroundings. Initial applications are expected to be in real estate, industrial, construction and heritage applications. In a few hours it is possible to create an electronic model without the need to visit the site. Uses could include building up virtual reality models or giving people a 'telepresence' elsewhere while taking part in meetings.
The system has been optimised to capture the interior as a human would see it, explains project manager David Leevers of Rickmansworth-based VERS Associates. The robots under development have approximately human dimensions and so are able
to go through doorways and scan at eye height.
The team is starting to get unique and promising results, says Leevers. The model is built up using a scanning laser range-finder to capture the 3D structure and a video camera to add the texture. A complete model is automatically assembled from many scans taken from different capture points.
At the heart of RESOLV is the EST head (Environmental Sensor for Telepresence) containing the scanner and camera. There are two prototype units. One is a trolley that has to be taken from place to place by the operator. The other includes an autonomous vehicle or robot in the base and can navigate throughout one floor of a building, capturing an area of say 50m by 50m overnight.
Trials of telepresence and construction applications are being used to refine the design. The system also allows users to see interiors from impossible positions, adds Leevers. 'One can rise above a building and see through any walls that are facing the other way,' he says.
Ways of looking at the model include viewing it directly in an Internet browser with VRML capability or combining it with CAD data to enhance interior visualisations. The foyer of the Royal Institution of Chartered Surveyors' headquarters and a living room are the examples currently on display on the Internet at http://www.scs. leeds.ac.uk/resolv/
RESOLV promises a whole new range of possible applications within the construction and real estate industry, Leevers believes. Traditional survey methods principally take two common forms: measured surveys and structural surveys with detailed visual and scientific inspection. In both cases, random and specific photographic and video data is often prepared as supporting information.
The 3D reconstruction will greatly enhance physical appreciation and spatial 'sense' by surveyors, their clients and third parties, he asserts.