You might remember back in Chapter 2, Starting Our First Project, that we touched very briefly on keyframes, those little recorded points in time that we use to animate objects. Blender uses tools that are very similar to using Timeline and Matinee in UE4, so let's spend a little bit of time building on that knowledge. Remember that keyframes represent important positions in time in our animations. In the case of our door, it was the open and closed positions. For our elevator, it was the up and down positions.

Those keyframes help Unreal and Blender to create what are called Tweens—all those little minor movements in between major points. Along with the keyframes, 30 of them make up one second of animation. Back in the heyday of Bugs Bunny, Road Runner, and the Flintstones, animation houses had Senior Animators, who would create all the keyframes. They would then turn those over to Junior Animators who would draw all of the tween frames by hand. This process...