nx_nxa_tier_pre_region_t143.nx

nx_nxa_tier.nx -- THE INGEST TIER LADDER FOR NXA ASSETS (/compare/modding MD5 ingest_tier_emit, 2026-09-05). WHY (measured 2026-09-05 on the served /world/beach cast through nx_nxa_play): every visiting-cast donor carries a COMPLETE rig (zero_weight_verts=0 on all five assets), and the cast still fails to arrive -- toon3d8.nxa is 61,939,208 B with 370 joints and 423,919 verts against the house girl's 11,728,120 B and 14,164 verts, and NOTHING on the ingest side emits a smaller tier, so the heaviest rip is served at full weight or not at all. This organ turns one NXA into a SMALLER NXA under a declared vertex budget, so a world can pick a door for every device (the scale-from-a-sensor-to-a-supercomputer law applied to assets). HOW: dense-grid vertex clustering (Rossignac-Borrel 1993, the same idea nx_mesh_decimate applies to an NxMesh) applied DIRECTLY to the NXA sections, with the cell size DERIVED by binary search so the result is the finest grid whose occupied-cell count fits the budget -- never a hand-picked cell. Each occupied cell becomes one vertex at the integer centroid of its members; the member NEAREST that centroid lends its SKIN row (four joints and q12 weights summing 4096, so no weight is ever invented) and its TEXC row (the bone-anchored UV, so the TEXM atlas still samples). Triangles are remapped and the collapsed ones (two corners in one cell) dropped. Sections that do not index vertices or triangles (SKEL ANIM POSE MATL TEXM HSTR) are copied verbatim with their checksums RECOMPUTED, never copied; any other section is DROPPED BY NAME and counted, because a per-vertex or per-triangle section this rung does not understand would silently desynchronise from the new VERT -- CLUS, MORF and the garment sections are the known cases and each is a later rung, not a silent loss. REFUSALS, each by name and each writing NOTHING: unreadable or corrupt input, no VERT or TRIS, a budget at or above the source vertex count (a tier is never an upsample), a budget under 3, a degenerate bbox. Usage: nx_nxa_tier <in.nxa> <out.nxa> <max_verts> nx_nxa_tier ladder <in.nxa> <out_prefix> [ladder.conf] rows tier|<id>|<max_verts>|<why> Exits: 0 ok | 2 usage | 3 refused-by-name | 5 missing section 100% sovereign, integer only. No hw writes (Rule 26). license_tier: ORIGINAL expect_exit: 0