Space-time volumetric depth images for in-situ visualization

Volumetric depth images (VDI) are a view-dependent representation that combines the high quality of images with the explorability of 3D fields. By compressing the scalar data along view rays into sets of coherent supersegments, VDIs provide an efficient representation that supports a-posteriori changes of camera parameters. In this paper, we introduce space-time VDIs that achieve the data reduction that is required for efficient in-situ visualization, while still maintaining spatiotemporal flexibility. We provide an efficient space-time representation of VDI streams by exploiting inter-ray and inter-frame coherence, and introduce delta encoding for further data reduction. Our space-time VDI approach exhibits small computational overhead, is easy to integrate into existing simulation environments, and may help pave the way toward exascale computing.