nx_ng_avatar_rig.nx

nx_ng_avatar_rig.nx -- CAP-NEURAL-AVATAR RUNG-2: the SKELETAL RIG. Extends nx_ng_avatar's 1-DOF single- gaussian deform to a multi-gaussian character driven by a multi-BONE skeleton via LINEAR BLEND SKINNING (LBS) -- the exact deformation math a DAZ Genesis figure / Unreal MetaHuman rig uses: each gaussian k's posed center = mu0[k] + SUM_b w[k][b]*pose[b] (a learned per-gaussian skinning weight w binds it to the bones). The KEY S-class rung toward beating DAZ/Unreal characters (shared primitive behind offline + real- time). Honest gated proof, Q16 no-float, reuses the gaussian-splat + GD-fit spine from nx_ng_avatar: T1 LEARNED-RIG: fit the skinning weights from posed frames -> loss->~0 AND w recovers the true binding. T2 NOVEL-POSE: an untrained skeleton pose renders correctly (LBS is linear = generalizes, not memorized). T3 NEG-CONTROL: a RIGID rig (all gaussians share one bone) CANNOT match a pose where the bones differ = the skeleton is load-bearing. T4 BIT-EXACT. HONEST: 1D positions, 2 bones, 2 gaussians, translation-LBS (no rotation), linear skinning. Full production = 3D + rotational LBS + blendshapes (expression) + many bones/gaussians = the follow-on rungs. Sovereign: nx_nofloat_autograd + syscalls. license_tier: ORIGINAL expect_exit: 0