GPU-Assisted Raycasting for Cosmological Adaptive Mesh Refinement Simulations

In the recent years the advent of powerful graphics hardware with flexible, programmable fragment shaders enabled interactive raycasting implementations which perform the ray-integration on a per-pixel basis. Unlike slicebased volume rendering these approaches do not suffer from rendering artifacts caused by varying sample distances along different ray-directions or limited frame-buffer precision. They further allow a direct realization of sophisticated optical models. In this paper we investigate the applicability of GPU-assisted raycasting to block-structured, locally refined grids. We present an interactive algorithm for artifact-free, high-quality rendering of data defined on this type of grid structure and apply it to render data of time-dependent, three-dimensional galaxy and star formation simulations. We use a physically motivated emission-absorption model to map the computed temperature and density fields to color and opacity.