Most of my research career has been about techniques to generate realistic images.
For example, a few years ago, Henrik Wann Jensen, Steve Marschner, Marc Levoy and I developed a simple approximation for simulating translucent materials, such as the marble in this bust of Diana the Huntress. The key physical idea that explains the appearance is subsurface scattering. Light crosses the surface, diffuses inside the material, and finally exits at a neighboring point. Comparing the two images, we see that translucent marble has a very pleasing appearance. Shadows are soft and bumps are deemphasized.
In our SIGGRAPH paper, which is typical of a realistic rendering paper, we made measurements of the scattering of light from translucent materials, and we claimed that we accurately modeled the physical appearance.