vascular surface without interference.

We do not differentiate between mesh or volume representations for vessel visualizations. Our only requirement to generate a VSS is the availability of a depth map which exhibits enough void space to be effectively utilized. While, based on our design goals, we tailored our visualization technique towards both, static 2D images and 3D interactive applications, it has to be considered that for example for 2D printouts not all depth cues can be applied to VSS. Such an example would be for instance the parallax effect.

The following subsections describe how we generate VSS and the visualization techniques we use to enhance depth and shape perception.

Surface Generation
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VSS are essentially view dependent height fields synthesized between vascular structures. To generate such a field, we interpolate the depth values of each pixel along the object’s silhouette which serves as a basis for subsequent visualization techniques. During interpolation, we also limit the amount of contour points considered for each pixel to the silhouette contours the pixel is enclosed by, in order to avoid a contribution of unrelated structures. The way the interpolated depth values are inferred for VSS is in principle arbitrary since there is no true 