Nicholas Frechette's Blog Raw bits
A quick recap: animation clips are formed from a set of time series called tracks. Tracks have a fixed number of samples per second and each track has the same length. The Animation Compression Library retains every sample while Unreal Engine uses the popular method of removing samples that can be linearly interpolated from their neighbors.
A quick recap: animation clips are formed from a set of time series called tracks. Tracks have a fixed number of samples per second and each track has the same length. The Animation Compression Library retains every sample while the most commonly used Unreal Engine codecs use the popular method of removing samples that can be linearly interpolated from their neighbors.
Two years ago I worked with Epic to try to improve the Unreal Engine animation compression codecs. While I managed to significantly improve the compression performance, despite my best intentions, a lot of research, and hard work, some of the ideas I tried failed to improve the decompression speed and memory footprint. In the end their numbers just didn’t add up when working at the scale Fortnite operates at.
Ever since the Animation Compression Library UE4 Plugin was released in July 2018, I have been comparing and tracking its progress against Unreal Engine 4.19.2. For the sake of consistency, even when newer UE versions came out, I did not integrate ACL and measure from scratch. This was convenient and practical since animation compression doesn’t change very often in UE and the numbers remain fairly close over time. However, in UE 4.21 significant changes were made and comparing against an earlier release was no longer a fair and accurate comparison.
Over the years, I picked up a number of tricks to optimize code. Today I’ll talk about one of them.