The [MT-FAIL] probe caught combat-stance monsters constantly failing to
dispatch 0x40000015 (Falling): their bodies were airborne-flagged while
standing. contact_allows_move (0x00528dd0) requires Contact+OnWalkable
and silently refuses every action animation for an airborne mover - a
spawned-standing monster's swings never played until it first moved.
Retail never has this state: CreateObject spawns run the placement
transition (CPhysicsObj::SetPosition -> SetPositionInternal 0x00515330),
which establishes CONTACT/ON_WALKABLE from the floor at spawn. Our
remote creation seeded a raw position with no placement.
SeedRemoteSpawnPlacement mirrors RemoteTeleportPlacement: engine
placement resolve (Setup-derived cylinder, TS-46) + the verbatim
CommitSetPositionTransition, wired at BOTH RemoteMotion creation sites
(UM-triggered creation - so a first-ever-UM attack animates in the same
packet - and ordinary first-UP creation). Unplaceable results leave the
body airborne exactly like a failed retail placement.
Also adds the [UM-ACT] (wire action items + stamp-gate verdict) and
[MT-FAIL] (refused animation dispatches) probes, riding
ACDREAM_DUMP_MOTION=1, which are what convicted the body state.
Complete Release suite: 10,032 passed / 5 skips / 0 failures.
Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>