When engineers working on a new bridge to run parallel to the Hoover Dam called on I-Site, an Australian company, to create a three-dimensional digital model of the dam, they were a bit sceptical. After all, the Hoover Dam, which sits some 30 miles southeast of Las Vegas, is renowned for its bulk as it stands some 724 feet (220 metres) tall.

But the Australians were undaunted. "Everyone thought we wouldn't be able to do it," says Bob Johnson, I-Site's managing director. "But our guys knocked it out in a couple of days." What they "knocked out" was an invaluable tool: an accurate 3-dimensional computer model of the dam and the surrounding area from which engineers could work as they designed the bridge.

In just a few years, I-Site, a subsidiary of Maptek, an Australian mining software company that Dr Johnson also heads, has become a small but aggressive player in a growing market for 3D imaging. It has annual sales of about A$1m but a 10 per cent share in a market that appears to have considerable growth potential, given the range of applications.

What I-Site sells is a laser device that scans the area around it by measuring and recording thousands of individual points in a matter of minutes. That data is then transferred into a personal computer where software developed by I-Site creates a three-dimensional model of the area scanned, even weaving together scans of the same area taken from different angles. For the Hoover Dam project, I-Site technicians used 17 different scan points around the dam.

The 15 I-Site systems, each worth some A$250,000, in place around the world are used for a variety of functions from helping animators digitise Hollywood film sets to assisting police investigators in the UK analyse accident scenes.

There are also potential applications for architects and surveyors and even agricultural companies looking for an accurate measure of things such as grain stockpiles.

The kind of 3D imaging I-Site provides is quick; it took just two hours to build a highly-accurate 3D image of the Sydney Opera House that could be used by architects or planners, for example.

But it also, Dr Johnson argues, removes many of the safety risks inherent in surveying things such as mines or the Hoover Dam. "With our machines no one has to go in and walk under rock overhangs," he says.

The small number of I-Site systems now in the field is largely related to cost and the company's relative youth. The product, a combination of re-badged scanners manufactured by Austrian company Riegl and I-Site software, was first marketed commercially in May 2000. Eventually the company wants to manufacture its own scanners and, as the cost of the machines comes down, set up a franchise model. But the privately-held I-Site with its staff of just 18 is not the only player in the market.

Leica Geosystems, the Swiss surveying instruments group, cited the growth prospects for 3D laser imaging when it bought out the remaining 80 per cent of Cyra Technologies, a Californian competitor of I-Site, for US$54m last year. At the time it boasted the acquisition would give it a dominant position in the 3D laser imaging market. Also competing for the market worldwide is Riegl, the Austrian manufacturer of I-Site's current hardware.

While Leica has a competitive advantage in its existing relationship with surveyors and now has more than half the market for 3D laser imaging, Dr Johnson believes I-Site has its own advantage in its parent company's long relationship with the mining industry. Maptek now holds more than half the market in mine management software, a niche that Dr Johnson estimates is worth somewhere between US$50m and US$100m.

And I-Site fits in with the company's current strategy of bolting on related niches as I-Site machines are already used by a number of miners. Dr Johnson says that growing from there seems a lot less daunting. "Measuring a building is a lot simpler than doing a scan of a gold mine in the rainforest," he argues.