Christmas came early: ACL 2.1 is out!
16 Dec 2023After over 30 months of work, the Animation Compression Library has finally reached v2.1 along with an updated v2.1 Unreal Engine plugin.
Notable changes in this release include:
- Added support for bind pose stripping which reduces memory usage by 3-5% on average
- Added support for loop handling through a looping policy
- Added support for pre-processing
- Added automatic compression level selection which reduces memory usage by 1-2% on average
- Optimized compression through dominant shell computation which reduces memory usage by up to 10%
- Added support for per sub-track rounding
- Updated to Realtime Math 2.2.0
- Many other improvements!
Overall, memory savings average between 10-15% for this release compared to the prior version. Decompression performance remained largely the same if not slightly faster. Compression is slightly slower in part due to the default compression level being more aggressive thanks to many performance improvements that make it viable. Visual fidelity improved slightly as well.
This release took much longer than prior releases because a lot of time was spent on quality-of-life improvements. CI now runs regression tests and tests more platforms and toolchains. CI uses docker which makes finding and fixing regressions much easier. A satellite project was spun off to generate the regression test data. Together, these changes make it much faster for me to polish, test, and finalize a release.
This release saw many contributions from the community through GitHub issues, questions, code, and fixes. Special thanks to all ACL contributors!
Who uses ACL?
The Unreal Engine plugin of ACL has proved to be quite popular over the years. The reverse engineering community over at Gildor’s Forums have a post that tracks who uses ACL in UE. At the time of writing, the list includes:
Desktop games: All latest Dontnod’s games: two last episodes of Life is Strange 2, Twin Mirror, Tell Me Why, most likely all their future releases as well. Beyond a Steel Sky, Chivalry 2, Fortnite (current version), Kena: Bridge of Spirits, Remnant: From the Ashes (current version), Rogue Company (current version), Star Wars: Tales From The Galaxy’s Edge, Final Fantasy VII Remake (including Intergrade), The Ascent, The Dark Pictures Anthology (Man of Medan / Little Hope / House of Ashes / Devil in Me) (current version), Valorant, Evil Dead: The Game, The Quarry, The DioField Chronicle, Borderlands 3, Tiny Tina’s Wonderlands, Medieval Dynasty (current version), Divine Knockout, Lost Ark, SD Gundam Battle Alliance, Back 4 Blood, KartRider: Drift (current version), Dragon Quest X Offline, Gran Saga (current version), Gundam Evolution (current version), The Outlast Trials, Harvestella, Valkyrie Elysium, The Dark Pictures Anthology: The Devil In Me, The Callisto Protocol, Synced (current version), High On Life, PlayerUnknown’s Battlegrounds (current version), Deliver Us Mars, Sherlock Holmes The Awakened, Hogwarts Legacy, Wanted: Dead, Like a Dragon: Ishin, Atomic Heart, Crime Boss: Rockay City, Dead Island 2, Star Wars Jedi: Survivor, Redfall, Park Beyond, The Lord of the Rings: Gollum, Gangstar NY, Lies of P, Warhaven (current version), AEW: Fight Forever, Legend of the Condor, Crossfire: Sierra Squad, Mortal Kombat 1, My Hero Ultra Rumble, Battle Crush, Overkill’s The Walking Dead, Payday 3
Mobile games: Apex Legends Mobile (current version), Dislyte, Marvel Future Revolution, Mir4, Ni no Kuni: Cross Worlds, PUBG Mobile (current version), Undecember, Blade & Soul Revolution (current version), Crystal of Atlan, Mortal Kombat: Onslaught (old versions), Farlight 84, ArcheAge War, Assassin’s Creed: Codename Jade, Undawn, Arena Breakout, High Energy Heroes, Dream Star
Console games: No More Heroes 3
Many others use ACL in their own internal game engines. If you aren’t using it yet, let me know if anything is missing!
What’s next
I’ve already started fleshing out the task list for the next minor release here. This release will bring about more memory footprint improvements.
If you use ACL and would like to help prioritize the work I do, feel free to reach out and provide feedback or requests!
Now that ACL is the default codec in Unreal Engine 5.3, this reduces my maintenance burden considerably as Epic has taken over the plugin development. This will leave me to focus on improving the standalone ACL project and Realtime Math. Going forward, I will aim for smaller and more frequent releases.