To create function curves in the FCurves window:

1. Select an object, such as a model.
2. Make sure the properties you want to animate are selected. For example, you can select Translation.
3. Select the time at which you want to set a keyframe.
4. Set a keyframe.
5. Move the timeline indicator, change the selected properties, and set a second keyframe.

   Interpolation is automatically created between the two keyframes. This interpolation is represented graphically as function curves in the FCurves window.

6. In the FCurves window, select the properties you animated, then click in the FCurves pane and press A to center the function curves.