The probe half of the master performance's ground model (binary
@4aa630-4aa6cc, via BT411's raw-asm decode), placed after Simulate's position
integration:
place the collision volume; drop a probe from the volume's authored bottom
(origin.y + collisionTemplate->minY); ask the zone's box tree what surface
lies under it (BoundingBoxTreeNode::FindBoundingBoxUnder); and if the query
hits (h > 1e-4), put the origin ON that surface exactly --
origin.y -= (h - lift).
The design is worth stating because it is not the obvious one: THERE IS NO
GRAVITY ANYWHERE IN THE MECH. Placement is absolute each frame. Walking
up-slope rides the lift window (an implicit step allowance), walking off a
roof drops instantly, and a probe MISS holds Y -- so a falling-through-the-
world runaway is structurally impossible rather than merely guarded against.
The engine side needed NOTHING reconstructed: Mover's own ctor already
builds collisionTemplate/collisionVolume from the model's BoxedSolidStream
resource and the zone tree was live all along. One include (boxsolid.hpp --
mover.hpp only forward-declares BoxedSolid, so the extents were an
incomplete type).
LIVE, arena run, no fault -- the y track tells the story by itself:
y = 20 -> 11.747 -> 10 -> 10 -> 0 -> 19.4049 -> 0
Spawn deck, down a ramp (caught mid-slope), an intermediate level, the arena
floor, up onto a structure, and off it. Every previous run had y pinned at
its spawn constant for the whole mission.
Deferred with the collision increment: frame rejection on blocking hits, the
crushable-icon sentinel, the crash clip (SetLegAnimation 0x20) on hard
impacts, and the gyro crunch feed.
Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
CydandClaude Fable 5
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