# Asset provenance

Author: **Quaternius**. Both source packs are CC0 1.0; included license texts are unmodified.

- Universal Base Characters, Standard: https://quaternius.com/packs/universalbasecharacters.html
- Official model download: https://quaternius.itch.io/universal-base-characters
- Universal Animation Library, Standard (with root-motion update): https://quaternius.com/packs/universalanimationlibrary.html
- Official animation download: https://quaternius.itch.io/universal-animation-library

Downloaded from the author's free download endpoints on 2026-10-16; no purchase, account or paid asset was used.

Source ZIP SHA-256:

- Base: `fdbf1804c90dfc1ea03e992bff7da2dfd1a79318e13270a660180f9308455f40`
- Animation: `cc73fc4e495b82958207316596317a3f40b9fa38065bde1027937452da537724`

Runtime derivatives:

- `athlete-base.glb`: `Superhero_Male_FullBody.gltf` plus its binary buffer, repackaged without external image textures. The 65-bone skin and original vertex weights are retained. Runtime vertex colors supply the two uniforms; helmet, pads and jersey number overlays are prototype additions.
- `animations.json`: selected authored clips retargeted offline to the male base using Three.js r170 `SkeletonUtils.retargetClip`, preserving the target bone lengths; sampled at 30 FPS. Full-body sprint comes from `Sprint_Loop`; running is no longer produced by the previous procedural leg solver. Ready, hold, throw, head-look and carry arm overlays are custom prototype layers.

The author describes these as animations created with an animator. This prototype makes no claim that they are motion capture, NFL recordings, or football-specific animations.

Three.js and its official addons are r170, MIT; see `../../vendor/LICENSE.three.txt`. No runtime CDN request is required.

Contact prototype: `Hit_Chest`, `Death01` and a held pose from `Fixing_Kneeling` are also retargeted from the same official animation pack. A custom `TackleSequence` coordinates the two actors' root positions, actual contact detection, torso/hand constraints, turf clearance and final hold. These are reused generic authored clips plus a controlled paired sequence, not a sourced football tackle pair or motion-capture claim.