Abstract: Subjective evaluation is one of the most important methods of assessing the fidelity of a virtual dynamic scene, whose results could be seen as a reference to improve a rendering method. In the present study, we apply a rendering method to the color rendezvous and docking (RVD) scene, where one shadow algorithm and three tone mapping operator algorithms are used to process the scene based on the distance between two spacecrafts. The grayscale RVD scene is transformed from the color RVD scene, and each RVD scene is desired to make comparisons with the real RVD-video recorded in SZ-10 mission. In addition, we perform an evaluation on 36 subjects to compare the results. The results show that shadow effects have important roles in RVD virtual scenes, where they enhance the sense of realism and immersion. Shadows, high brightness, contrast and luminance are highly correlated with the overall preference, and the grayscale scene receives better evaluations than the color scene. The analysis of these conclusions is vital for improving the algorithms used to render color virtual space scenes when virtual scenes for astronaut training in Chinese space station mission are prepared.

Key words: high dynamic range (HDR)| rendezvous and docking (RVD)| shadow rendering| subjective evaluation |virtual space scene

摘要： Subjective evaluation is one of the most important methods of assessing the fidelity of a virtual dynamic scene, whose results could be seen as a reference to improve a rendering method. In the present study, we apply a rendering method to the color rendezvous and docking (RVD) scene, where one shadow algorithm and three tone mapping operator algorithms are used to process the scene based on the distance between two spacecrafts. The grayscale RVD scene is transformed from the color RVD scene, and each RVD scene is desired to make comparisons with the real RVD-video recorded in SZ-10 mission. In addition, we perform an evaluation on 36 subjects to compare the results. The results show that shadow effects have important roles in RVD virtual scenes, where they enhance the sense of realism and immersion. Shadows, high brightness, contrast and luminance are highly correlated with the overall preference, and the grayscale scene receives better evaluations than the color scene. The analysis of these conclusions is vital for improving the algorithms used to render color virtual space scenes when virtual scenes for astronaut training in Chinese space station mission are prepared.

关键词: high dynamic range (HDR)| rendezvous and docking (RVD)| shadow rendering| subjective evaluation |virtual space scene