nx_pose_naturalness.nx

nx_pose_naturalness.nx -- Tier 6 biomechanical pose validation. CAPABILITY_COMPLETENESS: FULL User feedback 2026-05-16 (image #3 thread): "her pose was odd with her touching a wall." AI-generated poses often violate biomechanics: - Joint angles outside anatomical comfort range (wrist hyperextended, elbow inverted, etc.) - Center of mass outside support polygon (would fall over in real life) - Limb proportions wrong (one arm twice as long as other) This primitive checks two layers: Layer 1: Joint-angle comfort ranges (caller-supplied joint angles in Q10 degrees; substrate checks against named ranges). Layer 2: Center-of-mass-over-support (caller-supplied COM_x + support-point positions; substrate checks COM_x is within the support polygon's x-extent). References: - Whittle 2007 "Gait Analysis: An Introduction" (open excerpts) for joint comfort ranges - Winter 2009 "Biomechanics and Motor Control of Human Movement" (open excerpts) for COM analysis Joint comfort ranges (degrees; from American Academy of Orthopaedic Surgeons published joint motion guides): shoulder flexion: 0 to 180 shoulder extension: 0 to 60 shoulder abduction: 0 to 180 elbow flexion: 0 to 145 elbow hyperextension: 0 to 10 wrist flexion: 0 to 80 wrist extension: 0 to 70 hip flexion: 0 to 125