An article to enable the creation of a model of a surface includes a flexible substrate and multiple optical tracking points attached to the flexible substrate at predetermined location. The optical tracking points can be tracked by a tracking system, and a data link enables communication from the flexible substrate to a tracking system. Also disclosed is an article that enables the creation of a model of a surface including multiple light emitting diodes attached to the flexible substrate at predetermined locations. Finally, a method of registering an article and a method for creating a model of a surface having a shape are disclosed.