Release 0.22.0: Animation & deformation stack, Reach IK, and pack-loading performance

[untoldengine]

Summary

Release 0.22.0 adds a full animation and character-deformation stack built on pose layers, Reach IK targeting, and compute skinning, ships major scene- and pack-loading performance work, and fixes a set of scene lifecycle, export-fidelity, and threading bugs.

Animation and deformation

• Add the animation foundation and character deformation stack: pose layers, physics pose, compute skinning, DQS/DDM, morph targets, pose drivers, XPBD muscles, an ML deformer, and motion-capture seams ([Feature] Animation foundation and character deformation stack: pose layers, physics pose, compute skinning, DQS/DDM, morph targets, pose drivers, XPBD muscles, ML deformer, motion-capture seams #1259).
• Add Reach IK, letting a chain target a point in world, model, shoulder, or ground space ([Feature] Reach IK: a target per chain, in world, model, shoulder or ground space #1283).

Performance

• Build automatic LOD chains for the models of a .untoldpack ([Performance] Automatic LOD chains for the models of a .untoldpack #1299).
• Load each .untold in a pack once instead of once per reference, and write repeated models to a pack once ([Performance] Load each .untold of a pack once #1290, [Performance] Write repeated models once in a .untoldpack #1288).
• Read a mesh's Metal buffers from MetalKit once instead of per draw ([Performance] Read a mesh's Metal buffers from MetalKit once #1298).
• Register a loaded entity's transform once instead of redundantly ([Performance] Register the transform of a loaded entity once #1301).
• Leave objects under a pixel tall out of the frame ([Performance] Leave objects under a pixel tall out of the frame #1297).

Bug fixes

• Let scenes hold more than 20,000 entities ([Bugfix] Let scenes hold more than 20,000 entities #1289).
• Release ECS components when they leave the scene ([Bugfix] Release ECS components when they leave the scene #1300).
• Keep the root of a streamed scene in its hierarchy ([Bugfix] Keep the root of a streamed scene in its hierarchy #1304).
• Keep the transform and hierarchy of an entity that becomes a light ([Bugfix] Keep the transform and hierarchy of an entity that becomes a light #1303).
• Close a data race between Scene.assign and a reader of the slot ([Bugfix] Close the data race between Scene.assign and a reader of the slot #1302).
• Shade materials the way their values say: normal maps, emission, and reflections ([Bugfix] Shade materials the way their values say: normal maps, emission, reflections #1292).

Export and Blender add-on

• Keep an export's assets in a folder of their own ([Feature] Keep an export's assets in a folder of their own #1268).
• Export glass, and Blender's default bump heights, as they look ([Bugfix] Export glass, and Blender's default bump heights, as they look #1293).
• Remember failed texture writes per export instead of per Blender session ([Patch] Remember failed texture writes per export, not per Blender session #1263).

Docs and CI

• Update engine architecture docs (Updated recent engine architecture docs #1286).
• Document actors and locks: benchmark, lock census of the frame, and rules ([Docs] Actors and locks: benchmark, lock census of the frame and rules #1294).
• Skip build, test, and lint workflows for documentation-only changes ([CI] Skip the build, test and lint workflows for documentation-only changes #1295).

Checklist

• Relevant tests have been added or updated
• Existing functionality and API compatibility have been considered
• Relevant builds and tests pass locally
• Recoverable failures are handled appropriately
• Significant architectural changes and trade-offs are explained below
• Documentation has been updated where necessary
• Performance-sensitive changes have been measured, if applicable

Architectural notes / trade-offs

The animation stack (#1259) introduces pose layers as the composition point above physics pose, compute skinning (DQS/DDM), morph targets, pose drivers, XPBD muscles, and an ML deformer, with motion-capture seam handling folded into the same pipeline. Reach IK (#1283) targets per chain rather than per skeleton, with target space selectable as world, model, shoulder, or ground.

Pack loading now deduplicates both .untold reads and repeated model writes across a .untoldpack (#1290, #1288), and LOD chains are generated automatically for packed models (#1299) — this trades extra work at pack-build/load time for fewer redundant reads and smaller packs at runtime. Scene capacity beyond 20,000 entities (#1289) and the Scene.assign data race fix (#1302) touch core ECS/scene-concurrency paths and should be watched for regressions in high-entity-count and streaming scenes.