For the first time ever, historians can re-trace Napoleon's steps in a virtual reality replica of the battlegrounds at Waterloo, thanks to revolutionary 3D field laser-scanning technology. The centimetre-accurate replica of the site we created here at the University of Salford, was featured on the History Channel's Battlefield Detectives series on April 7th at 8pm. In partnership with FusionGFX and the Factuals Department at Granada Media we recreated buildings and woodland now long-vanished from the Waterloo battlefield.

Project Leader Andy Hamilton, from the School of Construction & Property Management, said: “Recreations of battlefields in television programmes and games environments have, until now, lacked the detail needed for in-depth analysis. This project has given historians a new insight into how the Battle of Waterloo was lost and won.”

The new scanning technology can also be used for other practical applications, such as the refurbishment of buildings. Using the scanner, the fine detail of a large building, inside and out, can be captured in a day. With this information it is possible to recreate architectural details, such as the ornamental stonework on the top of a building. We have a 3D printer that can produce a scalled or life-size plastic models of the details of buildings so that the item could be reworked in stone as part of the refurbishment process. We are also able to completely "reverse engineer" a building to produce Computer Aided Design files of plans and elevations, to support the refurbishment process.

THE INTELCITIES PROJECT
The INTELCITIES (Intelligent Cities) Project is a research and development project that aims at helping achieve the EU policy goal of the knowledge society. INTECLITIES project brings together the combined experience and expertise of key players from across Europe, focusing on e-Government, e-Planning and e-Inclusion, e-Land Use Information Management, e-Regeneration, Integration and Interoperability, Virtual Urban Planning, etc, (www.intelcitiesproject.com).

1. THE CONCEPTUAL SYSTEM OF BUILDING DATA INTEGRATION
The scope for the conceptual system of building data integration in the Intelcities project includes: integration of laser scanner technology with various systems such as CAD for 2D and 3D plans, with the GPS system for linking the OS data, with tools such as VR workbench, VR projection system, Video conferencing system, 3D printer for physical modelling and with the nD modelling repository for storing the information produced.

1.1 Real World Building Data Modelling
The laser scanner can provide reverse engineering in construction for the reuse of the existing facilities. Producing building design, CAD models and VR (Virtual Reality) models from an existing facility or groups of facilities, by means of the laser scanner, will facilitate an analysis of the latest conditions of the buildings taking into account the original drawings of the same buildings, if they still exist. Tthey even have the potential to accurately record inaccessible and potentially hazardous areas such as pitched rooftops. Consequently, it facilitates “virtual refurbishment” of the buildings and allows the existing structure and proposed new services to be seen in an effective manner.

1.2 3D Scanned data to nD modelled data (Ongoing research)
The research to date about object recognition from the laser scanned data is about pattern matching approach. Pattern Matching addresses issues of searching and matching strings and more complicated pattern such as trees, regular expressions, graphs, point sets, and arrays. As a result of various matching processes, object recognition can be worked out for the interesting building frames in the 3D CAD model. Attributes of the objects matched in the library will be assigned to the building frame in the CAD model resulting in an object-oriented (OO) CAD model which can then be stored in an nD modelling database.

LASER SCANNING FOR ENVIRONMENTAL PURPOSES
Terrestrial laser scanning offers solutions to a wide range of environmental measurement problems relating to landscape and feature documentation, resource quantification and topographic measurement and monitoring over many scales. The mobile technology and powerful post-processing techniques allow accurate measurement and digital representation of landscapes and features in any environment. This research also facilitates morphological auditing, elevation change mapping, landscape assessment and 2D and 3D flow modeling. Additional information is available at: www.els.salford.ac.uk/scanscape

Laser scanning uses a pulsed laser and time-of-flight principles to accurately measure physical surfaces in space. Each scan measures a physical scene and then digitally represents it in a relative coordinate system. Several scans from different perspectives may then be merged together to give a fully representative and accurate final model.

1. The Riegl LMS-Z210 Laser Scanner is very:
• fast (5 million points in 10 minutes)
• accurate (error of approximately 1cm)
• detailed (Model Resolution <1cm)
2. Non Destructive (No influence)
3. Versatile (many applications)
4. Appropriate Range (350m)
5. Excellent cost / performance ratio
6. High interference immunity
7. Small

The survey work, including terrestrial laser scanning, tachometry and photography, was completed over a 4-day period in April 2005 in and around Hougoumont Farm in Belgium. We explored the Hougoumont Farm site in order to identify the main points of interest and a reflector deployment pattern was created (reflectors are used to assist in the scan merging process, which creates a single model using scans from different locations, reflectors appear as bright white pixels in intensity scans). The entire battlefield site was scanned from the 30 different scanning locations identified in the deployment pattern so that data was captured all around the farm buildings, the courtyard and a nearby field that would have been a planted wood at the time of the battle. The coordinates of all the reflectors were recorded in the field using an Electronic distance Measurement Theodolite (EDM). The data that was captured maintained a high degree of detail even on small features including window frames and brickwork but also captured data on larger scale topography and building structure. Each scan contained approximately 1.5 million coordinate points with associated information including colour and reflectivity.

All buildings and surrounding features of interest where photographed at a high resolution for use as textures on the final virtual model. When taking these pictures we took into account time of year, time of day and weather conditions at the time of the Battle.

When we had completed the ‘on site' scanning and photography we took these individual sets of scan data back to the computers in the Virtual Planning Groups department at the University of Salford to merge all the scan data into one model.

Once all the extraneous data had been removed, the geometry of the model needed to be optimised using PolyWorks to refine and reduce the number of polygons, which resulted in a model suitable for manipulation in real-time virtual reality software. The model was then taken into a modelling package, MultiGen®s Creator™ , for further optimisation and enhancement. The optimisation was done in two phases, the first, grouping together various elements to create a structured hierarchy. The second phase was to introduce a ‘Level of Detail'. This meant examining each branch of the hierarchy, copying it and further reducing the number of polygons in it. This enabled either the high detailed branch to be shown when viewed close up or the low detailed branch to be shown when far away. This aids the processing speed when viewed real-time. Farm buildings and trees that have been removed over time were digitally added back into the virtual environment based on archaeological evidence, old maps and paintings.