Chapter 8: Creating Curves, Frames, and Tracks

In the early 2000s, it was common for games to take an animation that was authored in a 3D content creation tool such as Blender or Maya, play back the animation, and sample the transform of every joint in the animation at set intervals. Once the animation was sampled, the game's runtime linearly interpolated between the sampled frames.

While this works (and is doable with glTF files), it's not the most accurate way to play back animations. It wastes memory by including frames that don't actually need to exist. In a 3D content creation tool, animations are created using curves, such as the one shown in the following screenshot:

Figure 8.1: The Blender 3D curve editor

Modern games and animation systems evaluate these curves directly. Evaluating the animation curves directly saves memory, but curves are a bit more expensive in terms of processing power. By the end of this chapter, you should...