"Dude, you are so going to get fired" is what Silicon Valley colleagues told DARPA program manager Daniel Kaufman when he announced that he was going to talk about the problems and challenges of his RealWorld project.

The idea of RealWorld is to develop "simulations without software" and it has grown out of DARPA efforts to use commercial technology - much of it from the gaming world - to develop military training tools. Kaufman says that the effort "ran into two key problems. There was an enormous need and we needed more tools than we could ever build, and we don't build simulations quickly enough - I have air force friends who tell me that simulations are monuments to the way that the aircraft used to be."

The vision of RealWorld? "A 19-year-old can come back from a mission in Afghanistan where he ran into OPFOR and took fire. He can pull up a 3-D image of exactly where he was. He can drag and drop and say, I was there, my buddy was there, the Humvee was here and we took fire from there."

Challenges? One is to generate accurate 3-D images of urban terrain, using information from multiple sensors. "We want to create a market for new data sources," Kaufman says. But the toughest job will be to add people. "I want crowds, I want people with conflicting goals - the guy who wants to help but wants his family to be safe." But, he adds, the lurking question behind that is that "when we replicate the physical world it's easy to verify our accuracy - but with human factors, how do we know?"