Flat-panel displays might be all the rage, but at least in some situations, Microsoft thinks the shape of things to come might be a sphere.

After months of rumors, Microsoft researchers are taking the wraps off a prototype that uses an internal projection and vision system to bring a spherical computer display to life. People can touch the surface with multiple fingers and hands to manipulate photos, play games, spin a virtual globe, or watch 360-degree videos.

Sphere, as it's known, is expected to be shown publicly for the first time Tuesday at Microsoft's Faculty Summit in Redmond. For now, it's purely a research project. The company says it doesn't currently have plans to offer it as a product. The idea is to see what the technology can do, and how people will use it.

"It's really an exploration of ideas," explained Hrvoje Benko, the Microsoft researcher spearheading the project, during a sneak preview Monday afternoon.

Sphere is a cousin of the Microsoft Surface tabletop computer, already being used in retail and hospitality settings. The underlying hardware for Sphere is sold commercially by Global Imagination of Los Gatos, Calif., but Microsoft researchers made numerous enhancements and developed specialized software.

In a broader sense, the project reflects Microsoft's belief that many more surfaces will become computer displays, with embedded microprocessors, in the years to come. That view is championed by Craig Mundie, Microsoft's chief research and strategy officer, one of two executives filling Bill Gates' role at the company.

By their very nature, curved surfaces present unique challenges as computer displays. And in that regard, the sphere is the extreme example.

The Microsoft researchers came up with advanced algorithms to translate images originally intended for a flat computer screen so that they appear properly on the rounded globe, on the fly. They also added an infrared system that can sense when hands or objects are placed on the sphere, to let people interact.

"I believe what we are seeing is the emergence of various kinds of interactive surfaces," Benko said. "This is one surface that might be serving a particular purpose, but it should probably live in an ecosystem of other surfaces. So what's really interesting to us is what kinds of interactive surfaces we can make, how well we can make them, and how people interact with them -- how they are used."

In the spherical version of the classic Pong arcade game, for example, people can place their hands on the surface to direct bouncing balls around the sphere.

In another program, photos can be resized or dragged around the sphere in real time, or zapped quickly to someone on the other side of the sphere by pressing a palm against the surface. Another application lets people dip their fingers in virtual paint and press against the static globe as the digital canvas spins like a potter's wheel.

Among other technological tricks, the Microsoft researchers came up with a way to both sense objects on the surface and project onto the sphere through the same lens. That allowed them to keep all the required components inside, in the podium that holds the spherical screen. That was important, because aiming projectors or sensors at the sphere from outside would have caused problems including occlusion, where the bodies or hands of people using the Sphere would have gotten in the way.

Sphere will be shown Tuesday at the annual Microsoft Research Faculty Summit alongside other projects from Microsoft and university researchers.

Apart from the technological challenges, Microsoft researchers are interested in seeing how people will interact with the Sphere. It has been shown at internal Microsoft events, but the hundreds of university scientists and researchers attending the conference will be among the first from outside to give Sphere a try.