4D view synthesis: navigating through time and space

In this sketch, we present a 4D view synthesis technique for rendering large-scale 3D structures evolving in time, given a sparse sample of historical images. We built a system to visualize urban structure that is a function of the time selected, thereby allowing virtual navigation in space and time. While there is a rich literature on image-based rendering of static 3D environments, e.g., the Facade system [Debevec et al. 1996] and Photo Tourism [Snavely et al. 2006], little has been done to address the temporal aspect (e.g., occlusion due to temporal change). We construct time-dependent geometryto handle the sparse sampling. To render, we use time-andview-dependent texture mapping and reason about visibility both in time and space. Figure 1 shows the result of view synthesis based on time-dependent geometry.