A Concept of Effective Landmark Depiction

Landmarks represent elements of geovirtual 3D environments with outstanding importance for user orientation. Especially, they facilitate navigation and exploration within virtual 3D city models. This paper presents a novel concept for the real-time depiction of landmarks that effectively emphasizes these 3D objects by improving their visibility with respect to their surrounding areas and the current 3D viewing settings. The concept is based on scaling landmark geometry according to an importance function while simultaneously adjusting the corresponding surrounding region. The amplification of landmarks takes into account the current camera parameters. To reduce visual artifacts caused by this multi-scale presentation, e.g., geometry intersections, the surrounding objects of each landmark are adapted according to a deformation field that encodes the displacement and scaling transformations. An individual weight coefficient can be defined that denotes the landmark’s importance. To render a collection of weighted landmarks within a virtual 3D city model, the technique accumulates their associated, weighted deformation fields in a view-dependent way. Our concept provides a flexible solution for the importance-driven enhancement of objects within interactive geovirtual 3D environments and aims at improving the perceptual and cognitive quality of their display. In particular, the concept can be applied to systems and applications that use abstracted, generalized virtual 3D city models such as in the fields of car and pedestrian navigation, disaster management, and spatial data mining.