Schulze-Döbold, JürgenWössner, UweWalz, Steffen P.Lang, UlrichB. Froehlich and J. Deisinger and H.-J. Bullinger2014-01-272014-01-27200132118367131727-530Xhttps://doi.org/10.2312/EGVE/EGVE01/187-198This paper describes a flexible rendering system for scalar volume data which has been integrated into the visualization system COVISE. It allows direct volume rendering based on texture mapping hardware on both the desktop and in projection based virtual environments. Special care has been taken for the design and usability of the virtual reality user interface and for interactive frame rates. It features a new slider-less interaction window for the manipulation of the transfer function and methods for direct interaction with the volume data, such as a sub-volume probing mode. The interface has been evaluated in collaboration with a group of potential end users.