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BT411/game/reconstructed
Joe DiPrimaandClaude Opus 5 ee079083a3 #96: FIX -- normalise the myomer kinetic heat term to a reference frame rate
The previous commit only instrumented.  This is the behavioural change.

The binary's drive-heat integrator (FUN_004b8d18) multiplies its climb and accel
terms by the time slice but NOT the kinetic one:

    heat += ratio^2 * (1+dmg) * [ (1-accEff)*|vy|*m*g*dt
                                + (1-velEff)*(0.5*m*|v|^2)     <-- no dt
                                + (1-accEff)*|v|*|a|*m*dt ]

A per-TICK energy is a constant on a fixed-frame 1995 machine and a variable on a
modern PC: heat/second scales with frame rate, so two players on different
hardware -- or one player in a heavy scene versus an empty one -- get different
heat from identical throttle.  That is a defect independent of what the pod's
rate actually was.

The kinetic term is now multiplied by (dt * kPodFrameHz), which is exactly 1.0
when dt == 1/30 and makes the result machine-independent.  This is the one
deliberate divergence from a verbatim transcription of @004b8d18, and it is
marked as such in the source.

Measured, Owens at seek 4 flat out:
    before   crossed degradeT(1000) at ~27s, peaked 1213, settled ~710
    after    peak 1007, settled ~525
i.e. roughly halved at our measured ~59Hz, which is the direction the players
asked for ("too much IMO", "def need to tone down the myomer heat some").

⚠ CALIBRATION IS NOT PROVEN.  30Hz is the i860 BOARD frame ([T1],
rendering.md:177); the HOST simulation rate is not separately established, and no
fixed-timestep constant exists in the image (searched 1/15..1/60 and 30/60 Hz --
the arcade computed dt from a clock, as we do).  So the reference rate is the
best-documented value, not a proven one.  BT_MYO_HZ overrides it with no rebuild
so it can be calibrated by feel.

Precedent for the bug class, already logged in the KB: "trail density is
frame-rate-dependent (2/frame @60fps = 2x pod density)" (rendering.md:222).

NOT settled: whether the per-chassis ordering matches player memory (a Thor
sustaining seek 4 where a light chicken-walker cannot).  Post-fix benches put the
Thor HOTTER (crosses at 40s vs the Owens at 47s), but those runs are BT_GOTO
path-driven and the acceleration term is large and path-dependent, so they are
too noisy to conclude from.  The cooling data being identical across chassis IS
solid (measured, previous commit).

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
2026-08-01 13:34:44 -05:00
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