Chapter 5. Simulations in health and life sciences

The simulation of light interaction with human skin has been an object of extensive research in many fields for decades. Long before the first local lighting models appeared in the computer graphics literature, detailed biologically based models of light transport in organic tissue were already available in the scientific literature. In fact, most of the models proposed by the computer graphics community were built on modeling techniques developed and employed in those fields. Hence, to fully assess the efforts made by the computer graphics community toward the predictive modeling of skin appearance, it is essential to revisit seminal works that provide the basis for this line of computer graphics research. Furthermore, the modeling of skin optical properties continues to be an active area of theoretical and applied research in life sciences. However, the contributions of computer graphics to these efforts are still marginal. One of the key steps to change this situation is to strengthen the correctness and fidelity of the computer graphics simulations, which can be achieved by addressing data constraints and open problems from an interdisciplinary perspective.

In this chapter, we provide an overview of relevant simulation approaches and models of light interaction with human skin aimed at applications in health and life sciences. We start by briefly addressing the context in which these models are inserted, i.e., the application requirements that have influenced their design. The body of work on the modeling of tissue optics is quite extensive, and a comprehensive survey on this topic would require a entire book devoted to it. Hence, our discussion focuses on models that have been primarily aimed at the simulation of light and skin interactions. These models are grouped and examined according to the methodologies employed in their design. For more general information on topics related to the modeling of skin optics, the reader is referred to the texts by Cheong et al. [45], Tuchin [254], and Störring [241].