UC San Diego

I present a new algorithm to render multiple overlapping multi-channel volumes in real-time. The approach uses textured slices for rendering volumes and hardware- accelerated shaders for the application of transfer functions and the blending of data channels. Volume rendering is an important technique for visualizing scientific and biological data. The National Center for Microscopy and Imaging Research (NCMIR) images biological systems at multiple scales and resolutions using a variety of techniques. Visualization across scales is useful to scientists because 1) they often must combine multiple microscopies with different resolutions to understand a specimen; and 2) it is more efficient to take lower resolution views of broad expanses of tissue and higher resolution views of features of interest. Combining them together allows detail to be appreciated in context. Generating data sets at different levels of spatial resolution does not provide the precise coordinates required to co-locate, or superimpose the resulting volumes automatically. The algorithm enables users to interactively co-locate multiple nested volumes in real- time