(The Eurographics Association, 2006) Kaehler, Ralf; Wise, John; Abel, Tom; Hege, Hans-Christian; Raghu Machiraju and Torsten Moeller
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.