A new class of software emerges.

• Position: Video Games

A new class of software has been defined by researchers at Purdue University, West Lafayette, Ind. They are calling it "surrogate interaction," which enables designers and video gamers to change features of complex objects like automotive drawings or animated characters more easily This new approach is being used commercially and in research but, until now, had not been defined formally. Doing so could boost its development and number of applications, indicates Ji Soo Yi, assistant professor of industrial engineering.

Conventional computer-aided design programs often rely on the use of numerous menus containing hundreds of selection options. The surrogate interaction uses a drawing that resembles the real object to provide users a more intuitive interface than menus. The researchers have investigated the characteristics of surrogate interaction, explored potential ways to use it in design applications, developed software to test those uses, and suggested the future directions of the research.

Surrogates are interactive graphical representations of real objects, such as a car or video game character, with icons on the side labeling specific parts of the figure, explains Niklas Elmqvist, assistant professor of electrical and computer engineering. "If you click on one label, you change color; if you drag a border, you change its width. Anything you do to the surrogate affects the actual objects you are working with. The way it is now, say I'm working on a car design and want to move the rear wheels slightly forward, or I want to change an objects color or thickness of specific parts--I can't make those changes to the drawing direct, but have to search in menus and use arcane commands."

Several techniques have been developed over the years to address these issues, "but they are all isolated and limited efforts with no coherent underlying principle," Elmqvist notes. 'We propose the notion of surrogate interaction to...