Graph Editor

The Graph Editor is probably one of the scariest things you’ll see in Blender. Actually, it’s not that complicated, but usually the first time you see the animation curves without a proper understanding of how they work, they can look really complex.

In the Graph Editor, you’ll be able to edit the animation curves, also called F-Curves in Blender. But what are animation curves? They’re pretty simple.

When you create two keyframes, they are automatically interpolated by Blender. This means the value between two keyframes will smoothly transition from one to the other, as shown in the Figure 12.2. The curves define how the interpolation happens and you can control them to change that default interpolation in case you’re not happy with how it works.

Figure 12.2 Different curves that interpolate the same two keyframes

Each transform or property on each axis has an F-Curve. For example, say you want to make an object fly from one point to another; let’s see what would happen with different curve configurations (see Figure 12.2).

There are two keyframes in Figure 12.2. The horizontal position of a keyframe defines its time, while its vertical position sets its value. In this case, the first keyframe sets a value of 30 in the frame 0. The second keyframe sets a value of 120 in the frame 100.

The image to the left represents a linear interpolation, which tells Blender to increase the value from 30 to 120 between the frames 0 and 100 at a constant speed. The image to the right shows a smooth interpolation. With this type of interpolation, Blender first starts increasing the value slowly, then it accelerates, and finally it decreases its speed slowly before reaching the value of 120 at the frame 100. As you can see, these are two different movements between the exact same keyframes and they are defined by the animation curves.

In the Graph Editor, you can manipulate curves as always by moving, rotating, or scaling keyframes using G, R, and S. You can also duplicate curves with Shift + D.

To change the interpolation mode of a keyframe, you can select it and press T (you can also do this in the Dope Sheet, but the difference is more visual in the Graph Editor). A menu will appear with different options for setting the interpolation and the handle type of that keyframe. In the Graph Editor, selecting one or more keyframes and pressing V will let you select different positions for those keyframe’s handles, which will also affect how the interpolation works.

You can adjust handles by right clicking and dragging to modify the curvature of the interpolations and control how you want the animation to accelerate or to make the animation smoother. Another way of adjusting the handles is to select a keyframe and rotate it or scale it; you will also change the orientation and size of its handles when you do this.