FCurve

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.^[1][2]

This visual graph of keyframes allows one to see the value of the key and its interpolation to the next key, which shows the animation "ease ins" and "ease outs".

F-Curves support various interpolation methods, including:

• Linear Interpolation: Creates a straight line between keyframes, resulting in uniform motion.
• Bézier Interpolation: Provides smooth transitions by allowing control over the tangents, enabling more complex motion profiles.
• Custom Interpolation: Animators can manipulate the curve manually to achieve specific motion dynamics, such as quick starts or slow finishes, by adjusting the handles of the Bézier curves^[3]