The port's target pick was a whole-mech bounding-box slab test, and every hit
-- aimed or not -- dispatched zone -1 into the victim's cylinder lottery. The
recovered 1995 model (the division-card scene intersection) struck a SEGMENT
and credited that segment's own damage zone. This is the port's equivalent.
At render-tree build, each segment's draw object and its PrimaryDamageZone --
authored per segment in the skeleton stream, read by JMOVER.cpp:290 -- are
recorded in MechRenderTree::segPick. The pick (BTL4VideoRenderer::
MechSegmentPick) ray-tests the per-segment bounding spheres on the live posed
skeleton, using the draw-cached mLocalToWorld (at most one frame stale, fine
for aiming).
Selection is SPECIFICITY-FIRST: among the spheres the ray pierces, the
smallest radius wins, normalized-distance tie-break. Both obvious rules were
measured failing the same way before this one: the torso mesh's sphere
(r~4.1 on the MadCat, vs shoulders at r~1.0) envelops nearly the whole mech,
so its front face is nearest for any aim AND any near-body ray normalizes to
~0 against it. Limb spheres nest inside the envelope; smallest-pierced picks
the most specific part on the aim line, and the torso wins only when no limb
is threaded -- the per-part semantic the pod's mesh test produced.
mech4.cpp tries the segment pick per candidate; the box PickRayHit survives
only as the fallback (no tree yet, wrecked, spectator), still carrying zone
-1 into the lottery, and a structure occlusion clears the zone. The winner's
zone rides MECH_TARGET_SUBIDX + targetReticle.targetDamageZone into
SendDamageMessage, so aimed hits now dispatch a real zone; the victim's
handler applies it directly (bursts 2+ still re-lottery, authentic per the
recovered @0x4a0230 loop).
Bench, the same L/C/R sweep that exposed the bug: aiming left now lands
36/41 hits on zone 2 = jointlshoulder -- the left arm -- with a 0.30 thread
score, where the same aim was a 6-way lottery spray before. The MadCat's
authored segment->zone map is rich (shoulders 2/9, guns 6/17, hip 1, six leg
zones, torso 0). Known approximations, flagged for field verification:
sphere bounds rather than triangles, and a torso-envelope graze credits the
torso where the pod's exact mesh test would have missed into air.
The field protocol is the one the testers already ran on night 6: stationary
mechs, short range, fire only at one arm -- the paper doll should now damage
THAT arm.
Diag: BT_PICK_LOG ([segpick] map at build, [pickwin] per pick).
Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
