IRIS: Illustrative Rendering for Integral Surfaces

Abstract

Fig. 1. A path surface generated from a turbulent jet dataset, rendered in two different styles using the framework proposed in this paper. In the left image, the surface is opaque, and the front and back side are rendered with yellow and blue, respectively. An adaptive stripe pattern visualizes individual pathlines on the surface and provides the orientation of the flow. On the right, the surface is rendered transparently with a denser stripes to give a hatching-like appearance. Both figures emphasize surface silhouettes for better distinction of individual surface layers.Abstract-Integral surfaces are ideal tools to illustrate vector fields and fluid flow structures. However, these surfaces can be visually complex and exhibit difficult geometric properties, owing to strong stretching, shearing and folding of the flow from which they are derived. Many techniques for non-photorealistic rendering have been presented previously. It is, however, unclear how these techniques can be applied to integral surfaces. In this paper, we examine how transparency and texturing techniques can be used with integral surfaces to convey both shape and directional information. We present a rendering pipeline that combines these techniques aimed at faithfully and accurately representing integral surfaces while improving visualization insight. The presented pipeline is implemented directly on the GPU, providing real-time interaction for all rendering modes, and does not require expensive preprocessing of integral surfaces after computation.

Interactive Virtual Probing of 4D MRI Blood-Flow

“…Various illustrative renditions of pathsurfaces were presented in recent work [2,10]. Similar to Hummel et al [10], we apply a stripe pattern to enhance the surface shape.…”

“…Garth et al [7] have described a generic hardware-accelerated approach for generating pathsurfaces, while Bürger et al [3] presented a real-time technique for the generation of streak surfaces. Recently, Born et al [2] and Hummel et al [10] introduced distinct illustrative visualization styles for integral surfaces. In particular, Hummel et al [10] proposed to enhance perception of the surface shape by stripe patterns.…”

“…Recently, Born et al [2] and Hummel et al [10] introduced distinct illustrative visualization styles for integral surfaces. In particular, Hummel et al [10] proposed to enhance perception of the surface shape by stripe patterns. We have adopted similar stripe patterns for our application-specific pathsurfaces.…”

“…Similar to Hummel et al [10], we apply a stripe pattern to enhance the surface shape. The stripes are procedurally generated in the fragment shader, allowing interactive color mapping of various derived measures of the blood-flow.…”

Parallel stream surface computation for large data sets

“…Garth et al [9], Hummel et al [13], and Born et al [2] recently investigated advanced rendering techniques including nonphotorealistic rendering and better texture mapping to achieve improved visual depictions of stream surfaces (cf. Figure 3).…”