Opacity-modulating triangular textures for irregular surfaces

Many scientific and medical visualization techniques produce irregular surfaces whose shape and structure need to be understood. Examples include tissue and tumor boundaries in medical imaging, molecular surfaces and force thresholds in chemical and pharmaceutical applications, and isosurfaces in a wide range of 3D domains. The 3D shape of such surfaces can be particularly difficult to interpret because of the unfamiliar, irregular shapes, the potential concavities and bulges, and the lack of parallel lines and right angles to provide perspective depth cues. Attempts to display multiple irregular surfaces by making some or all of them transparent further complicates the problem. Texture can provide valuable cues to aid in the interpretation of irregular surfaces. Opacity-modulating textures offer a mechanism for the display of multiple surfaces without the extreme loss of clarity of multiple transparent surfaces. This paper presents a method for creating simple repeating textures and mapping them onto irregular surfaces.