Nicholas Frechette's Blog Raw bits
Every compression algorithm covered herein is lossy in nature, so how we measure accuracy is critically important. Measured deviation from source data needs to be representative of the visual differences observed.
Animation clips more or less always boil down to the same thing: a series of animated tracks. There might also be other pre-processed data (such as the total root displacement, etc.) but we won’t concern ourselves with this since their impact on compression is usually limited. Instead, we will focus on bone transform tracks: rotation, translation, and scale.
Central to character animation is our animation sequence. These are also commonly called animation clips and I will use both terms interchangeably.
This post is meant as a preface to explain the overall context of what is character animation, how we use it, and why it needs special consideration.
Character animation compression is an exotic topic that seems to need to be re-approached only about once per decade. Over the course of 2016 I’ve been developing a novel twist to an older technique and I was lucky enough to be invited to talk about it at the 2017 Game Developers Conference (GDC). This gave me the sufficient motivation to write this series.