nx_partloft_capture_t319.nx

nx_partloft_gate.nx -- THE LOFTED PART (nx_partloft_lib) HELD TO KNOWN ANSWERS (procgen PG59 / anatomy AN19, 2026-09-19). A straight cylinder of known radius decomposes into the genes the source's decompose_nurbs_handles would produce (centred skeleton, equal proportions, zero pitch, zero lateral drift, a unit-circle profile facing +x), recomposes to its own handles within the millimetre quantisation, evaluates as a cubic B-spline whose radius is constant around the ring and clamped to the end rows, and writes a WATERTIGHT NXMSH2 whose every directed edge has exactly one reverse twin. A bent part built from genes survives the decompose-recompose round trip in its pitch. The gene mutation is the identity at var = 0 (byte-identical genes), moves the radii at var = 1, keeps its pitch noise zero-mean, and is deterministic per seed. Surface coordinates (t, yaw, rad) land where apply_attach_transform's ray would: yaw 0 is straight down, a half turn is +y, rad 0 is the skeleton itself. NEG-CONTROLS: a cone must read as a cone (the decomposer discriminates radii), a shape the cubic cannot carry must be refused by name, and a face size that leaves no cap fan must be refused rather than floored. license_tier: ORIGINAL. No hw writes (Rule 26).