When visualising datasets that are too large to be displayed in their entirity,
interactive navigation is a common solution. However, instantaneous updates of
the visualisation when navigating can result in disruption to the
user's mental map. Animated transitions are one way of addressing
this problem. This paper presents the Data-Model-View-Controller (DMVC)
architecture for navigation-based interactive systems. Navani, a software
framework based on DMVC for supporting animated transitions during navigation,
is presented, along with a sample application of it to hierarchical data.