An Evaluation Study of preferences between combinations of 2D look shading and Limited Animation in 3D computer animation

抄録

3D computer animation has become popular all over the world, and different styles have emerged. However, 3D animation styles vary within Japan because of its 2D animation culture. There has been a trend to flatten 3D animation into 2D animation by using 2 D look shading and limited animation techniques to crea te 2D looking 3D computer animation to attract the Japanese audience. However, the effect of these flattening trends in the audience’s satisfaction is still unclear and no research has been done officially. T herefore, this research aims to evaluate how the combination s of the flattening techniques affect the audience’s preference and the sense of depth. Consequently, we categorized shadings and animation styles used to create 2D look 3D animation, created sample movies, and finally evaluated each combinatio n with Thurston’s method of paired comparisons. We categorized shadings into three types; 3D rendering with realistic shadow, 2D rendering with flat shadow and outline, and 2.5D rendering which is between 3D rendering and 2D renderin g and has semi realisti c shadow and outline. We also prepared two different animations that have the same key frames; 24fps full animation and 12fps limited animation, and tested combinations of each of them for the evaluation experiment. The result of the study showe d that peop le prefer 24fps to 12fps, and 2.5D rendering to the other renderings. It also presented a cultural difference in which Japanese spectators tend to like 2D rendering more than 3D rendering, but spectators of other nationalities tend to like 3D rendering mor e than 2D rendering. 2D look 3D animation is beneficial in some degree for Japanese audience; however, there seems to be room for exploring new styles between 2D and 3D to attract more audience.