13 - 18 OCTOBER 2013, ATLANTA, GEORGIA, USA

Lightness Constancy in Surface Visualization

Contributors: 
Danielle Albers, Alper Sarikaya, Michael Gleicher
Description
Color is an effective and commonly used channel for displaying data in surface visualization. However, color is affected by shadows and shading, which convey depth and shape on surfaces. The human visual system has evolved constancy mechanisms for identifying color under varying illumination conditions. Lightness constancy allows people to accurately perceive colors in real shadows; however, its effectiveness in surface visualizations is not well understood. We report a series of initial studies that confirm the existence of lightness constancy effects on molecular surface renderings. We evaluate common design decisions to show how choices of attenuation, color ramp, and shading model impact viewers' abilities to accurately identify colors on molecular surfaces rendered with ambient occlusion. Our findings lead to a set of generalizable design implications for effective surface visualization using color.