Subjective Evaluations of Appearance of Fabric Images Drawn by Computer Graphics and Influence of Rendering Parameters

Abstract

Using the computer graphics images of fabric that were produced with the Oren-Nayar-Blinn model and the Oren-Nayar model in computer graphics software, we examined the rendering parameters (“Specular”, “Diffuse”, and “Roughness”) of images which give similar subjective impression to actual fabric. We also considered the influence of the parameter values on subjective impression of the images. The result showed that when the parameter “Diffuse” was equal to 90 or 100, and the parameter “Roughness” was equal to 30 in both models, the subjective evaluations were the most similar to those of real fabric. It was also shown that the value of the parameter “Diffuse” greatly contributed to the appearance of fabric: as the value increased, the appearance of fabric images became brighter, softer, and smoother.