Illustrative Volume Visualization for Unstructured Meshes Based on Photic Extremum Lines

Scientific visualization techniques create images attempting to reveal complex structures and phenomena. Illustrative techniques have been incorporated to scientific visualization systems in order to improve the expressiveness of such images. The rendering of feature lines is an important technique for better conveying surface shapes. In this paper, we propose to combine volume visualization of unstructured meshes with direct rendering of illustrated iso surfaces. This is accomplished by extending a GPU-based ray-casting algorithm to incorporate illustration with photic extremum lines, a type of feature lines that captures sudden change of luminance, conveying shapes in a perceptually correct way.