From Success Stories in Scientific Visualization Wiki
An important problem in the automated design of visualizations is how to label and annotate real and virtual objects effectively. This can be especially challenging when the objects to be annotated and the viewer all reside in a dynamic 3D world. Naïve approaches can result in ambiguous labels and important objects being obscured by less important ones. This image shows the output of an interactive annotation system, photographed through a see-through head-worn display from the perspective of one user in a test-bed collaborative augmented reality environment. Two users are sitting across from each other discussing a virtual campus model located between them. All campus buildings have been labeled with their names; each label is scaled within a user-selectable range and positioned automatically. A label is placed either directly within a visible portion of its building’s projection, or if the visible parts of the projection are deemed too small to accommodate a legible label, the label is placed near the building and connected to it with an arrow, while avoiding overlap with other objects. Additional annotations include a meeting agenda (left), and a building model and information sheet (right). All annotations have been constrained to avoid other objects, including the visible user’s head, to allow a direct line of sight between the two users. The result is that annotations remain legible and clearly associated with the objects to which they are related, even as the users move. Challenges include supporting a richer range of spatial constraints, better addressing graphic design considerations, and developing systems that can choose constraints to fulfill on the fly as users’ tasks change.
B. Bell, S. Feiner, and T. Höllerer, "View management for virtual and augmented reality", Proceedings of UIST 2001 (ACM Symposium on User Interface Software and Technology), Orlando, FL, November 11–14, 2001 (CHI Letters, vol. 3, no. 2), 101–110.
