  Exploring large virtual environments, such as cities, is a central task in
several domains, such as gaming and urban planning. VR systems can greatly help
this task by providing an immersive experience; however, a common issue with
viewing and navigating a city in the traditional sense is that users can either
obtain a local or a global view, but not both at the same time, requiring them
to continuously switch between perspectives, losing context and distracting
them from their analysis. In this paper, our goal is to allow users to navigate
to points of interest without changing perspectives. To accomplish this, we
design an intuitive navigation interface that takes advantage of the strong
sense of spatial presence provided by VR. We supplement this interface with a
perspective that warps the environment, called UrbanRama, based on a
cylindrical projection, providing a mix of local and global views. The design
of this interface was performed as an iterative process in collaboration with
architects and urban planners. We conducted a qualitative and a quantitative
pilot user study to evaluate UrbanRama and the results indicate the
effectiveness of our system in reducing perspective changes, while ensuring
that the warping doesn't affect distance and orientation perception.
