Abstract: An article of sports apparel such as an outsole for a shoe may be formed based on a computational traction profile. The computational traction profile is built based on received sensor data, such as that obtained by a frustrated total internal reflection (“FTIR”) system having a surface on which an individual may perform a movement. The sensor data is obtained while a different article of sports apparel of the same type is worn by the person during an activity. The sensor data may be used to alter a visual outsole pattern, traction features such as projections or recesses, for example. One or more of the position, height, cross-sectional shape, and the like of the respective projections and recesses may be varied along the surface of the outsole in response to the computational traction profile.