nx_myo.nx

nx_myo.nx -- PIPELINE STAGE 2: VOLUME-PRESERVING MUSCLE BOUND TO BONE. The industry's second stage is "volume-preserving meshes bound to the bones to calculate authentic muscle bulging and flexing". An audit found this stage completely untouched in our stack: what we called muscle was ONE scaled envelope at 82 percent of the skin radius -- a shell, not a muscle, bound to nothing, conserving nothing, incapable of bulging. ★THE DEFINING PROPERTY, and the reason this is a real muscle rather than a bump that grows: VOLUME IS CONSERVED. A muscle belly is very nearly incompressible, so when its ends are drawn together it does not simply get shorter -- it must get THICKER by exactly the amount that keeps its volume constant. That is why a flexed biceps bulges, and it is a hard arithmetic constraint rather than an artistic choice: length x cross-section = constant => radius = r0 * sqrt(L0 / L) A generator that merely thickened a muscle by some tuned factor would look approximately right and be unfalsifiable. This one is checkable: measure the volume before and after and it must not move. BOUND TO BONE: a muscle spans an ORIGIN on one bone and an INSERTION on another, so flexing the joint between them shortens it and the bulge follows from the joint angle -- no separate muscle animation, no hand-authored bulge curve. The joint angle is the only input. nx_myo <origin_len> <flex_deg> -> the muscle's state at that joint angle nx_myo selftest license_tier: ORIGINAL expect_exit: 0 No hw writes (Rule 26).