An FCurve (also written f-curve) is a function curve or the graph of a function. An example of a FCurve is a spline. In the field of computer animation and especially in animation editors, e.g. Maya, an FCurve is an animation curve with a set of keyframes, which are represented as points, curve segments between keys, and tangents that control how curve segments enter and exit a key. These keys are laid out on a graph that displays their position relative to zero. One can have keys that are either positive or negative values.