Resumen: This paper presents a time-varying, multi-layered biophysically-based model of the optical properties of human skin, suitable for simulating appearance changes due to aging. We have identified the key aspects that cause such changes, both in terms of the structure of skin and its chromophore concentrations, and rely on the extensive medical and optical tissue literature for accurate data. Our model can be expressed in terms of biophysical parameters, optical parameters commonly used in graphics and rendering (such as spectral absorption and scattering coefficients), or more intuitively with higher-level parameters such as age, gender, skin care or skin type. It can be used with any rendering algorithm that uses diffusion profiles, and it allows to automatically simulate different types of skin at different stages of aging, avoiding the need for artistic input or costly capture processes. Idioma: Inglés DOI: 10.1111/cgf.12540 Año: 2015 Publicado en: COMPUTER GRAPHICS FORUM 34, 2 (2015), 45-55 ISSN: 0167-7055 Factor impacto JCR: 1.542 (2015) Categ. JCR: COMPUTER SCIENCE, SOFTWARE ENGINEERING rank: 17 / 106 = 0.16 (2015) - Q1 - T1 Factor impacto SCIMAGO: 0.806 - Computer Networks and Communications (Q1) - Computer Graphics and Computer-Aided Design (Q1)