Files
Syplheed-Reborn/docs/re/flight-speed-law.md
Claude (auto-RE) 6c7025851e re(flight): the rate probe measures a MOVING speed -- pitching bleeds it hard
Measured pitch with the rows properly pinned, against this craft's own disc caps
(AV_PitchPlus_Min 150, AV_PitchPlus_Max 70):

    min speed (LT)  1391.0 deg / 8.00 s, clock x1.326 -> 131.1 deg/game-s  vs 150
    max speed (RT)   989.0 deg / 8.05 s, clock x1.318 ->  93.2 deg/game-s  vs 70

A rate 33% ABOVE a cap is not a finding, it is a broken instrument. The HUD speed
is in the same bracketing screenshots that give the clock, so read it:

    slow phase   102 ->  18
    fast phase  1193 -> 589

The speed is NOT constant during the dwell -- pitching halves it in 8 seconds.
The cap is speed-dependent, so as the craft slowed its cap rose, and an 8-second
average necessarily lands between the max-speed cap and a mid-speed one. The 133%
is entirely the instrument.

This also weakens the roll result committed earlier: same method, so 120.9 vs
AV_Roll_Max 125 is CONSISTENT but is not a tight test -- the true cap could be
lower and still produce that average. Said plainly in the doc rather than left
standing as a clean confirmation. Min-speed figures are less affected; there is
little speed left to lose.

Proper fix, not yet done: dwell ~1-2 s so speed barely moves, or sample HUD speed
continuously and fit rate against INSTANTANEOUS speed -- which yields the whole
rate-vs-speed curve instead of two points.

Separately this is a flight-model finding: TURNING COSTS SPEED, steeply, with the
throttle still at maximum. A reimplementation treating the throttle as a speed the
craft simply holds will be wrong during manoeuvres.
2026-08-13 22:48:29 +00:00

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# The throttle is a TARGET-SPEED selector — measured against the definition (2026-08-13)
**Status: ✅ for the shape of the law, 🟡 for the unit scale.**
The unit definition gives `MinimumVelocity 100`, `CruisingVelocity 350`,
`MaximumVelocity 1200`, `Acceleration 600` and `Deceleration 500` for
`UN_f001_TCAF_DeltaSaber_T_Player` ([values](captures/unit-runtime-fields.csv)),
but not **how** the game applies them. This measures it.
Method — [`tools/re-capture/speed_law.py`](../../tools/re-capture/speed_law.py):
lock onto the player entity once, then sample its own position triple in guest RAM
while holding each throttle input in turn (8 s per phase, 20 Hz). Speed is
differentiated over **1-second windows**, never per sample.
## Result
| phase | measured speed (1 s windows) | settles to | definition field |
|---|---|---|---|
| no throttle | 367 403 471 365 463 463 365 | **~420** | `CruisingVelocity` 350 |
| `RT` held | 1041 1376 1551 1379 1596 1510 1620 | **~1 530** | `MaximumVelocity` 1200 |
| release | 1314 672 432 452 432 450 408 | back to **~440** | — |
| `LT` held | 203 121 135 121 115 146 122 | **~125** | `MinimumVelocity` 100 |
| release | 369 451 427 425 445 390 465 | back to **~430** | — |
So the throttle **selects a target speed** and the craft converges to it; releasing
either trigger returns it to cruise. (**Refined below**: the trigger is analogue, so
the target is a continuous interpolation and these three are its endpoints.) It is not a
force model with the throttle adding thrust, which is what a reimplementation would
most likely have assumed from `Acceleration`/`Deceleration` alone. Those two fields
govern the **convergence rate**: the release phase falls ~1 314 → ~432 in about two
seconds (~440 units/s², against `Deceleration` 500) and the `RT` phase climbs ~420 →
~1 550 in two to three seconds (~470560 units/s², against `Acceleration` 600).
## 🟡 The unit scale
Measured world-space speeds run **≈1.21.3× the definition numbers** in all three
regimes (cruise 1.21, maximum 1.28, minimum 1.32). The HUD, meanwhile, reads
**350** at cruise — the definition value exactly. So the definition's velocity unit
is the HUD's, and entity world coordinates are a constant multiple of it, close to
**1.25**. The spread across regimes is larger than the constant itself is precise,
because the craft is manoeuvring under fire while sampled (straight-line
displacement per window under-reads a curving path), so this is recorded as a
measured range rather than a pinned constant.
## Traps
* **`RT`/`LT` are analogue triggers**, so `vgamepad trig RT 1.0` holds the throttle;
the button verb `hold RT` is a **silent no-op**. The first run of this probe
measured the drift of a craft nobody was flying.
* **Do not differentiate per sample.** The guest updates the position slower than
20 Hz, so per-sample differences alternate between 0 and a double step —
`0, 1519, 1985, 0, 2681…` for a craft flying smoothly.
* **Bind late, measure fast.** The player entity is not in the typed-entity scan
for the first ~15 s of a mission, and the craft dies within a few minutes if
nobody is flying it — one earlier attempt ended at `GAME OVER` mid-probe.
Raw samples: [`captures/speed-law-throttle-phases.csv`](captures/speed-law-throttle-phases.csv).
---
# Turn rates: `AV_*` are rate caps, and `_Min`/`_Max` mean *at minimum/maximum speed*
`tools/re-capture/turn_law.py` pins the speed regime with a throttle, holds a stick
axis, and differentiates the craft's **own forward vector** over 1-second windows.
**Control mapping, measured**`LX` is **roll** (the forward vector barely moves
under it: 35 °/s residual), `LY` is **pitch** (`vgamepad` documents `LY: -1 = up`,
so `+1` is nose down = the `PitchMinus` family), and the **right stick does not
steer at all** (0 °/s).
| phase | measured (1 s windows) | definition |
|---|---|---|
| slow + nose down | 85 · 96 · 82 → **~87** | `AV_PitchMinus_Min` **75** |
| fast + nose down | 55 · 45 · 63 → **~54** | `AV_PitchMinus_Max` **40** |
| slow + nose up | 181 · 164 · 181 → **~175** | `AV_PitchPlus_Min` **150** |
| fast + nose up | 103 · 130 · 175 → **~136** | `AV_PitchPlus_Max` **70** |
Two claims of the field names are confirmed:
* **Agility falls with speed** — every rate drops when the throttle goes from `LT`
to `RT`, so `_Min`/`_Max` are *at minimum / maximum speed*, not floor/ceiling of
the rate.
* **Pitching up is about twice as fast as pitching down**, exactly as the pair
150/75 (slow) and 70/40 (fast) says.
## The ~1.2× factor — ⚠️ WITHDRAWN, see "Settled rates match exactly" below
The speed law measured 1.21 / 1.28 / 1.32 × its definition values; the pitch rates
measure 1.16 / 1.35 / 1.17 / 1.94 × theirs. A **unit scale** would have to differ
between metres-per-second and degrees-per-second — it cannot explain both. A **time
base** does: if the guest's simulated second is shorter than the wall-clock second
this probe measures against, every rate reads high by the same factor. So the
definition numbers are self-consistent and a reimplementation should take them at
face value; these measurements confirm the **shape** of the law (which field governs
what, and how the regimes switch), not a scale correction.
🟡 **No yaw input was found.** `AV_Yaw_{Min,Max}` (45 / 25 °/s) exists, but neither
stick yaws the craft. With `MaximumBank_Normal` (60) and roll on `LX`, a
**bank-to-turn** model is the obvious reading — sustained turns come from rolling and
pitching — but the yaw fields may equally belong to the AI or to an input this probe
has not driven.
Raw samples: [`captures/turn-law-pitch-phases.csv`](captures/turn-law-pitch-phases.csv).
---
# The afterburner is not on the obvious buttons — a bounded negative
The definition describes the burner without naming its input: `AB_ConsumeShield_Begin`
**50**, `AB_ConsumeShield` **10**, and a set of `AB_AV_*` turn caps far below the
normal ones (roll 40 vs 125200 °/s, pitch-up 30 vs 70150). Notably there is **no
`AB_*Velocity`**, so the burner may not raise the speed target at all.
Two independent probes, both negative for `A`, `B`, `X`, `LB` (and `LS`/`RS` on the
first):
* [`tools/re-capture/ab_probe.py`](../../tools/re-capture/ab_probe.py) — hold `RT`
for a max-speed baseline, then hold each candidate: speed stayed inside the
baseline's own noise band (1 2001 580 units/s) for every one.
* [`tools/re-capture/ab_state_probe.py`](../../tools/re-capture/ab_state_probe.py) —
sample a window of the player object while each candidate is held and report any
float that falls during the hold: **nothing fell**.
* And the cheapest oracle of the three, needing no offsets at all: **count the green
pixels of the HUD's SHIELD bar** before and after each hold, on a freshly spawned
craft with a full shield. `AB_ConsumeShield_Begin 50` should take a visible bite;
the bar read **156, 156, 156, 157, 157** across baseline and all four buttons.
So the burner is **not a simple hold on `A`/`B`/`X`/`LB`/`LS`/`RS`**. What remains:
a chord (something plus `RT`), an input this pad cannot reach, a craft variant that
has it, or fields that belong to the AI rather than the player. Worth knowing before
anyone re-probes the obvious buttons.
(`RB` is the nose gun, `Y` the missile mount and the d-pad the tactical map — see
[flight controls](flight-controls-runtime.md) — so those were not held here.)
---
# The throttle is ANALOGUE: the target speed interpolates cruise → maximum
`RT` is an analogue trigger, so "held" was only ever one point on a curve. Walking
it in five steps ([`tools/re-capture/throttle_curve.py`](../../tools/re-capture/throttle_curve.py),
2.5 s to converge then 5 s of sampling per step):
| `RT` | settled speed (1 s windows) | mean |
|---|---|---|
| 0.00 | 465 · 411 · 373 · 504 | **438** |
| 0.25 | 648 · 554 · 678 · 622 | **626** |
| 0.50 | 739 · 961 · 897 · 919 | **879** |
| 0.75 | 1028 · 1086 · 977 · 1283 | **1094** |
| 1.00 | 1359 · 1306 · 1517 · 1186 | **1342** |
A straight ramp. Dividing by the ~1.2 time-base factor established above, the
endpoints land on the definition's own numbers — 438/1.2 ≈ **365** against
`CruisingVelocity` **350**, and 1342/1.2 ≈ **1118** against `MaximumVelocity`
**1200** — and the midpoint follows: 879/1.2 ≈ 733 against the predicted
350 + 0.5·(1200350) = 775. So
```
target speed = CruisingVelocity + RT · (MaximumVelocity CruisingVelocity)
```
and `LT` mirrors it down to `MinimumVelocity`**measured**, see below.
**This also refutes a live hypothesis about the afterburner.** Full `RT` producing
more than `MaximumVelocity` looked like it might *be* the burner; it is not — the
curve is smooth through full deflection, with no step, and the shield does not move.
Full throttle is simply full throttle.
Raw samples: [`captures/throttle-curve-rt.csv`](captures/throttle-curve-rt.csv).
(The entity scan that locks onto the player searches *changing* position triples, so
it only sees the craft while it still has speed — bind early, or a mission left
idling drops out of the scan entirely and every tool reports "player entity not
found" while the game is visibly flying.)
---
# `LT` mirrors `RT`, and roll does NOT depend on speed
One flight, both measurements
([`tools/re-capture/flight_law2.py`](../../tools/re-capture/flight_law2.py)).
## The braking half of the curve
| `LT` | 0.00 | 0.25 | 0.50 | 0.75 | 1.00 |
|---|---|---|---|---|---|
| speed | 436 | 379 | 289 | 209 | **126** |
A straight ramp down from cruise to ~126, and dividing by the ~1.2 time-base factor
the endpoints are the definition's own numbers again — 363 against
`CruisingVelocity` **350** and 105 against `MinimumVelocity` **100**. So the throttle
law is symmetric:
```
RT held: target = Cruising + RT · (Maximum Cruising)
LT held: target = Cruising LT · (Cruising Minimum)
```
## Roll
Roll turns the craft about its own forward axis, so it has to be measured on a
different row of the rotation matrix than pitch was:
| phase | rate per 1 s window | mean |
|---|---|---|
| minimum speed + full roll | 171 · 103 · 157 | **~144 °/s** |
| maximum speed + full roll | 140 · 145 · 164 | **~150 °/s** |
**Roll shows no speed dependence** — the two regimes agree inside the noise, where
pitch dropped by a third to a half between them. Against the definition
(`AV_Roll_Min` 200, `AV_Roll_Max` 125) the measured ~145 °/s is ~121 after the
time-base factor, i.e. **the `Max` value in both regimes**.
So the `_Min`/`_Max` pair does *not* mean the same thing for every axis: pitch
interpolates between them with speed, roll appears pinned at `Max`. A
reimplementation that applies one rule to all axes would get roll wrong at low
speed by ~60 %.
🟡 Caveat kept: the roll phases were 2 s of settling apart, which is marginal for a
full 126 → 1 342 speed change, so "no dependence" is a measurement over a real but
not perfectly separated pair of regimes.
Raw samples: [`captures/throttle-curve-lt.csv`](captures/throttle-curve-lt.csv) ·
[`captures/turn-law-roll.csv`](captures/turn-law-roll.csv).
---
# ⚠️ Settled rates match the definition EXACTLY — the "time base" reading is withdrawn
The earlier turn measurements settled each phase for 1.5 s and then differentiated
from the first second. Re-running with **5 s of settle** and the craft's speed
recorded *at the moment the turn starts*
([`tools/re-capture/flight_law3.py`](../../tools/re-capture/flight_law3.py)):
| phase | speed at turn | measured rate | definition |
|---|---|---|---|
| pitch, minimum speed | 130 /s | **74.9 °/s** | `AV_PitchMinus_Min` **75** |
| pitch, half throttle | 388 /s | 73.7 °/s | (between, see below) |
| pitch, maximum speed | 1 821 /s | **41.1 °/s** | `AV_PitchMinus_Max` **40** |
| roll, minimum speed | 110 /s | 129.5 °/s | `AV_Roll_Min` 200 |
| roll, maximum speed | 1 722 /s | 149.3 °/s | `AV_Roll_Max` 125 |
**Pitch lands on 75 and 40 — the definition's own numbers, with no scale factor.**
So the ~1.2× I attributed to the emulated time base was an artefact of measuring
during the `AA_*` acceleration ramp with too little settle, and that explanation is
**withdrawn**: angular rates need no correction, and a reimplementation should use
`AV_*` verbatim.
What remains unexplained is only on the **linear** side: settled speeds still read
high and vary between runs (`RT` full measured 1 342 in one flight and 1 821 in
another, against `MaximumVelocity` 1 200), which is what a craft being shoved around
in a firefight looks like. The HUD, meanwhile, reads exactly `CruisingVelocity` at
neutral throttle. A clean linear measurement wants a quiet corner of a map, not this
one — until then, no cause is claimed.
**Roll, re-measured with proper settles, confirms the axis difference**: 129.5 at
110 /s and 149.3 at 1 722 /s — no speed dependence, both near `AV_Roll_Max` **125**,
where pitch moved 75 → 40 across the same range. The mid-throttle pitch point does
not discriminate lerp-versus-switch, because at half throttle the craft only reached
388 /s, where an interpolation would predict ~66 °/s against a measured 73.7 — inside
this probe's noise.
Raw samples: [`captures/turn-law-settled.csv`](captures/turn-law-settled.csv).
---
# The linear discrepancy is real, and it is between WORLD units and DISPLAYED speed
Last section removed the "time base" explanation by showing settled *angular* rates
match the definition exactly. That leaves the linear side, and the HUD settles it:
screenshotting the speed readout at each throttle step, next to the position-derived
measurement of the same moment
([`captures/throttle-curve-hud.csv`](captures/throttle-curve-hud.csv)):
| `RT` | HUD readout | position-derived | ratio |
|---|---|---|---|
| 0.00 | **350** (= `CruisingVelocity`) | ~447 | 1.28 |
| 0.25 | **507** | ~652 | 1.29 |
| 0.75 | **963** | ~1 141 | 1.19 |
Two things follow.
* **The HUD speaks the definition's language.** It reads exactly `CruisingVelocity`
at neutral and climbs toward `MaximumVelocity` as the trigger is pressed — 963 at
three-quarters, against the 987 the interpolation predicts. So the throttle law
stated above is confirmed in the game's *own* units, independent of any position
sampling.
* **World displacement runs ~1.2× the displayed speed.** Since the angular rates
need no such factor, this is not a clock effect: it is a **unit difference between
the position triple and the velocity fields**. A reimplementation that places
entities in world coordinates and moves them at `MaximumVelocity` will be ~20 %
slow.
🟡 The ratio is 1.191.29 across the three points rather than a clean constant, and
every sample was taken in a firefight where the craft is also being pushed. Pinning
it exactly wants a quiet map or a scripted straight run; the *existence and rough
size* of the factor is what these measurements support.
**A methodological note worth keeping.** This line of work went: hold a trigger →
"three target speeds" → analogue interpolation → an unexplained 1.2× → "time base"
→ withdrawn → a *unit* difference confined to the linear side. Every step came from
one of two moves: **let a held input vary** (the trigger's analogue range), or
**bring in an independent oracle** (the HUD, the definitions, a longer settle). The
wrong turn — the time base — came from explaining a number instead of first
measuring the same quantity a second, cleaner way.
---
# ✅ The linear factor IS the clock — measured against the game's own mission timer
The cleanest possible version of the linear measurement: neutral throttle (HUD reads
exactly `CruisingVelocity` 350), sticks centred, **20 s of perfectly straight flight**
(`straightness = displacement/path = 1.000`, so no manoeuvring contaminates it) —
[`tools/re-capture/cruise_ratio.py`](../../tools/re-capture/cruise_ratio.py):
```
displacement 8 900 world units in 20.1 s -> 443.6 /s
ratio vs the HUD's 350 -> 1.267
```
And the game's **own clock**, read off the HUD across a wall-clock interval:
```
mission TIME 00:08.79 -> 00:46.97 = 38.18 s of game time
wall clock = 30.29 s
ratio = 1.260
```
**1.260 against 1.267 — the same number.** So the linear "discrepancy" was never a
unit difference: **the mission clock runs ~1.26× faster than wall time under this
emulator**, and a speed derived by dividing world displacement by *wall* seconds is
inflated by exactly that. World units and the displayed speed share one unit, and a
reimplementation should take `CruisingVelocity`/`MaximumVelocity` at face value —
per **game** second.
This supersedes the previous section's "world-unit vs displayed-speed difference".
**One thing does not fit, and is left open.** The settled turn rates measured
74.9 and 41.1 °/s *in wall time* against `AV_PitchMinus_{Min,Max}` 75/40 — but if
game time runs 1.26× fast, a 75 °/game-second cap should have read ~94 °/wall-second.
Either that agreement was luck inside a noisy sample (the per-window rates spanned
6196), or angular integration is frame-based where linear is time-based. The check:
re-measure pitch and convert wall→game seconds with the clock ratio, expecting ~94
if the clock explanation is universal.
---
# ✅ The clock factor applies to the ANGULAR side too — and it varies per run
The open question was whether the ~1.26× mission-clock factor explains only the
linear measurements. Measuring **both in the same run** settles it
([`tools/re-capture/pitch_gametime.py`](../../tools/re-capture/pitch_gametime.py):
HUD screenshots bracket each turn phase, so the mission clock's own advance converts
wall seconds to game seconds):
```
this run's clock: TIME 00:33.68 -> 00:44.12 = 10.44 s game in 7.96 s wall = 1.311
```
| phase | wall-time rate | ÷ 1.311 → game-time | definition |
|---|---|---|---|
| pitch, minimum speed | 88.9 °/s | **67.8 °/s** | `AV_PitchMinus_Min` **75** (0.90×) |
| pitch, maximum speed | 53.6 °/s | **40.9 °/s** | `AV_PitchMinus_Max` **40** (1.02×) |
So with the clock correction both land on the definition (the slow phase runs 10 %
low, consistent with the `AA_*` ramp being included in an 8 s window). **The clock
explanation is universal**: every rate the game states is per **game** second, and a
probe that divides by wall seconds reads high by that run's ratio.
**And the ratio is not a constant of the machine — it varies with scene load**:
1.260 in the earlier flight, **1.311** here. It has to be measured *in the same run*
as whatever it is correcting, which is why this probe brackets its own phases with
HUD screenshots.
Bonus confirmation from the same screenshots: at full `LT` the HUD reads **102**,
against `MinimumVelocity` **100** — the throttle law's lower endpoint, in the game's
own units.
## The trap that cost three runs: a dead emulator looks alive
A killed Canary leaves **both** its `/dev/shm/xenia_memory_*` image *and* its last
frame on the X display. So the screenshot shows a mission in progress, the memory
image still parses, and the scans quietly report `0 moving triples` / "player entity
not found" — which reads like a tooling bug. `pgrep -x xenia_canary` does **not**
help: zombies match it. `speed_law.require_live_emulator()` now checks the process
*state letter* and refuses to measure a corpse, naming the stale image in its error.
---
# ⚠️ The roll result is WITHDRAWN — the probe was not isolating roll
Re-running the roll phases with 5 s settles and in-run clock brackets
([`tools/re-capture/roll_gametime.py`](../../tools/re-capture/roll_gametime.py)):
```
this run's clock: TIME 00:34.93 -> 00:45.97 = 11.04 s game in 7.98 s wall = 1.383
minimum speed: 90.6 °/wall-s ÷ 1.383 -> 65.5 °/game-s (AV_Roll_Min 200)
maximum speed: 59.1 °/wall-s ÷ 1.383 -> 42.7 °/game-s (AV_Roll_Max 125)
```
Two things are wrong with reading this as "roll".
* The corrected numbers — **65.5 and 42.7** — are within a few per cent of the
**pitch** run's **67.8 and 40.9**. Two different stick axes producing the same
rates is the signature of a measurement that is not separating them.
* Watching a non-forward matrix row sees **any** rotation that moves that row, and
pitch moves it as much as roll does. The forward row was the wrong thing to avoid;
what is needed is the rotation **about** the forward axis — project the row onto
the plane perpendicular to forward and track the angle of that projection.
So the earlier conclusion — *"roll shows no speed dependence, unlike pitch"* — is
**withdrawn**. It rested on 2 s settles (which this session has twice shown to
produce wrong answers) and on a row that mixes the axes. The two runs do not even
agree with each other (144/150 then, 90.6/59.1 now), which is itself the tell.
What survives: `AV_Roll_{Min,Max}` are **not** confirmed, and the axis question —
does roll follow the same speed rule as pitch? — is **open**, with the correct
measurement specified above.
**The clock ratio has now been measured three times in three flights: 1.260, 1.311,
1.383.** It is not a property of the machine but of the moment, so any rate probe
must bracket its own phases.
## Roll, re-measured about the forward axis — the withdrawal is reversed ✅
The earlier roll result was withdrawn because the *measurement* was wrong, not the
input: watching a non-forward row of the rotation matrix sees **any** rotation that
moves that row, and pitch moves it as much as roll, which is why two different stick
axes produced the same rates. `tools/re-capture/roll_axis.py` measures rotation
**about** the forward axis instead — express the new up-vector in the old
`(up, right)` basis and take `atan2(u_new·w_old, u_new·u_old)`, so any component
along forward (what pitch produces) is dropped by construction.
Run on stage 02 with the container-safe file pad, which matters here: the pad state
is written whole, so the stick is deflected on **exactly one axis** (`lx=32767`,
every other channel exactly 0) while the throttle trigger is held in the same write.
5-second settles, 8-second dwells, and each phase bracketed by HUD-clock screenshots
because the clock ratio is a property of the moment (1.260/1.311/1.383 previously).
| phase | swept | wall | HUD clock | per **game** second | definition |
|---|---|---|---|---|---|
| min speed (`LT`) | 1 856.9° | 8.01 s | 01:20.64 → 01:30.63 (×1.247) | **185.9 °/s** | `AV_Roll_Min` **200** |
| max speed (`RT`) | 1 181.2° | 8.02 s | 01:37.11 → 01:46.88 (×1.218) | **120.9 °/s** | `AV_Roll_Max` **125** |
**Roll DOES depend on speed**, and the withdrawn claim ("roll shows no speed
dependence, unlike pitch") is **reversed**. Roll behaves exactly like pitch: the rate
cap falls as speed rises, and `_Min`/`_Max` mean *at minimum / at maximum speed*
the same rule the pitch work established, now confirmed on a second axis rather than
contradicted by it.
Both measurements land **just under** their caps (93 % and 97 %), which is the right
side for a rate limit. 🟡 The shortfall is not explained: candidates are the craft not
being exactly at min/max speed after 5 s, and the swept-angle sum slightly
undercounting at 20 Hz. Neither is worth a claim without measuring it.
Method note: the tell that the *old* result was broken was two conditions agreeing
too well (pitch ≈ roll). The tell that this one is sound is that they now **disagree
in the direction the definitions predict**, on two independently-bracketed phases.
Data: [`captures/roll-about-forward-axis.csv`](captures/roll-about-forward-axis.csv).
## Which input drives which axis — and the yaw answer ✅
`tools/re-capture/axis_probe.py` holds one channel at a time (file pad, so every
other channel is exactly zero) and decomposes the result into **all three** rotation
components at once, rather than measuring one axis through a row that moves under any
rotation — the flaw that once made roll and pitch produce identical numbers.
**The row labelling is measured, not assumed.** `entities2` pins row 2 = forward
against velocity; the probe pins the other two by comparing **world-Y** in flight:
```
row world-Y means: [0.469, 0.883, -0.000] forward = row 2
-> up = row 1, right = row 0 CONFIDENT
```
That is the **opposite** of the D3D convention an earlier run assumed, which means
that run's *yaw* and *pitch* columns were swapped — under the correct labels its
`ly+` reading of 154.1 °/wall-s is **pitch**, which is what a left-stick Y axis
should do.
| input | roll | yaw | pitch | |
|---|---|---|---|---|
| `rx` right-stick X | 0.0 | 0.0 | 0.0 | nothing |
| `ry` right-stick Y | 0.0 | 0.0 | 0.0 | nothing |
| `LB` | 0.0 | 0.0 | 0.0 | nothing |
| `RB` | 0.0 | 0.0 | 0.0 | nothing (it is the nose gun) |
| `lx` left-stick X | 209.8 | ~0 | ~10 | **roll** |
| `ly` left-stick Y | ~0 | ~0 | 154.1 | **pitch** |
These zeros are **trustworthy**, unlike the previous attempt's: the four unknown
inputs were measured *first*, each passing a liveness check, and the run aborted the
moment the craft stopped moving instead of reporting the clean zeros a destroyed
craft produces.
**So no pad input yaws the craft directly.** `AV_Yaw_*` (45/25) exists in the unit
definitions but nothing on the right stick or the shoulders drives it — the earlier
*"no input found"* is upgraded from "we could not find one" to **"the remaining
candidates measurably do nothing"**. The natural reading is that yaw is a
*consequence* of banking rather than a commanded axis, which a reimplementation
should model as such.
🟡 Not covered: the **d-pad** (the tactical map) and the **face buttons** (fire /
weapon select). Neither is a plausible flight axis, but neither was measured here.
Data: [`captures/axis-probe-rows-pinned.csv`](captures/axis-probe-rows-pinned.csv).
## ⚠️ Angular-rate probes measure a MOVING speed — the dwell bleeds it
Measuring pitch with the rows properly pinned gave, for
`UN_f001_TCAF_DeltaSaber_T_Player` (whose own disc values are
`AV_PitchPlus_Min` **150°**, `AV_PitchPlus_Max` **70°**):
| phase | swept | clock | per game-s | cap |
|---|---|---|---|---|
| min speed (`LT`) | 1 391.0° / 8.00 s | ×1.326 | **131.1** | 150 |
| max speed (`RT`) | 989.0° / 8.05 s | ×1.318 | **93.2** | 70 — **133 % of cap** |
A rate 33 % *above* a cap is not a finding, it is a broken instrument, so read the
HUD speed off the same bracketing screenshots that gave the clock:
```
slow phase 102 -> 18
fast phase 1193 -> 589
```
**The speed is not constant during the dwell — pitching bleeds it hard**, halving it
in 8 seconds. The rate cap is itself speed-dependent, so as the craft slowed its cap
*rose*, and the 8-second average necessarily lands between the max-speed cap and a
mid-speed one. The 133 % is fully explained by the instrument.
**This weakens the roll numbers above as well.** They were taken the same way, so
`120.9` vs `AV_Roll_Max` `125` is *consistent* but is **not a tight test** — the true
max-speed roll cap could be lower and still produce that average. The min-speed
figures are less affected (there is little speed left to lose).
**How to measure it properly** (not yet done): keep the dwell to ~12 s so the speed
barely moves, or sample the HUD speed continuously and fit rate against
*instantaneous* speed rather than assuming the endpoint. The second is strictly
better and gives the whole rate-vs-speed curve rather than two points.
**And a flight-model finding in its own right:** *turning costs speed*, steeply —
1 193 → 589 under 8 s of full pitch, with the throttle still held at maximum. A
reimplementation that treats the throttle as setting a speed the craft simply holds
will be wrong during manoeuvres. Data:
[`captures/pitch-rate-speed-bleed.csv`](captures/pitch-rate-speed-bleed.csv).