ImageVis3D is a volume rendering application specifically designed to render large data sets. This is achieved by splitting the data set into multiple levels of detail (LoD), with each level itself decomposed into multiple bricks (atomic rendering primitives). Interaction occurs at the coarsest LoD, which can be rendered instantaneously on almost all modern systems. After a configurable delay, ImageVis3D will successively render finer levels of detail, until the data are visible at their native resolution. Volume rendering, as the name implies, is a technique for rendering scalar volumes of data. The rendering method allows one to see "inside" a data set, allowing the user to understand the inner three-dimensional structure of the data.