Many animations are a kind of record of natural events. Using their professional skills, animators record portions of natural events in animations. In this report information of natural events in cell animations is argued on the concept of the ecological approach to perception and action proposed by J. J. Gibson. Gibson noted that ambient light fills the environment, and that it constitutes an optic array. Surfaces of objects reflect light, so the component of the optic array is unique to the surface. Natural events include motion of surfaces. These motions produce transformations in the optic array. This transformation should be the invariant as specific in formation of the event. Consider the flow of air in wind. Air is invisible but wind causes visible changes in the environment. It is suggested that perception of wind velocity be based on transformation of surface that is uniquely related to the Reynolds number, a non-dimensional number developed in fluid dynamics. The trial analysis of some animation treating with wind shows that the unique transformation patterns related to the Reynolds number may specify the winds velocity, and that winds have both order and irregularity. This research will contribute to study visual perception and describe skills of animators.