Kaehler, RalfWise, JohnAbel, TomHege, Hans-ChristianRaghu Machiraju and Torsten Moeller2014-01-292014-01-2920063-905673-41-X1727-8376https://doi.org/10.2312/VG/VG06/103-110In 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.Categories and Subject Descriptors (according to ACM CCS): I.3.3 [Computer Graphics]: Picture/Image Generation Vieweing Algorithms I.3.7 [Computer Graphics]: Three-Dimensional Graphics and Realism Raytracing