You can use round surfaces as well with the system I made, as long as as the markers themselves are flat. And you can use Frame Markers as well, which isn't possible with the Multi Target system at the moment. Have a look here:
http://ar.qualcomm.at/node/2001030

Currently flat surfaces are required, sorry!

- Kim

Many thanks Kim. The cereal box is composed of flat surfaces. I am wondering about more complex 3D models with complex, curvilinear surfaces.

You can use 3D objects that are made up of multiple image targets, so each face must be planar and feature-rich (e.g. a cereal box). Read up on Multi Targets in the Dev Guide.

- Kim