In this paper we advocate the use of a focal region-guided feature-based volume renderer that offers an alternative for visualization of internal structures of volumetric data. We describe this promising technique for communicating the first impression of object shape or contour while at the same time providing detailed information of volumetric data with the use of lens-like focal region. We designed a method for generating object contours and enhancing volumetric features of the volumetric data to depict context information out of focal region based on gradient volume. In the focal region, we render interesting volume data using the direct volume rendering method. We obtain different objects in focal region through specifying object specific transfer functions. The rendering is guided by focal region through which we can specify what subset to render. The connection between the structure of inside and outside of focal region gives a better understanding of spatial relationship. This is to better communicate the existence, form, and location of underlying targets while minimally occluding them.
