Closes Phase 4's outstanding action-sequence-correctness invariant, then
fixes two server-side bugs an adversarial review of that work uncovered.
Server simulation, bot observations, collision resources and tick rate are
unchanged: the server_physics_parity trace is byte-for-byte identical to
HEAD across 360 ticks including both ships' full observation vectors.
4.11 - prediction history filed under the ISSUING sequence
_send_local_input filed each post-step predicted state under the timeline's
estimate of the sequence the server would consume this tick, trailing
issuance by input_lead. The body had integrated the intent issued under
_input_seq, so predicted[S] held "state after the intent from now" while
the server's authority for S is "state after action(S)". They agree only
while the stick is still. Filing under _input_seq costs nothing: which
action the ship uses is decided in LocalNetShipController.get_action() and
is untouched.
Every prior Phase 4 gate held its input steady, and a steady input cannot
falsify a sequence label - the 60s runs honestly reported marker=0/3784.
New --exercise-input-transitions role toggles thrust every 6 ticks; it is
the only gate that can catch a label regression. Verified non-vacuous: the
old label fails it at 50%.
4.12 - issued-but-unsimulated sequences, and the release path
An attack (delta > 1) issues and sends several sequences for one local
physics step. Those gap sequences had no recorded prediction, so a server
ack of one reported missing_not_recorded - indistinguishable from ring
loss, costing a teleport and resync suppression several times a minute.
They are now recorded stateless via record_unsimulated() and answered with
a new "skip" decision mode. Free-flight hard snaps: 25/8/4 -> 0/0/0.
A release (delta == 0) re-recorded at the unchanged _input_seq, filing the
current intent under a sequence that went out carrying a different action;
LocalInputTimeline deliberately refuses to mutate an issued sequence, so
the ring contradicted the wire. Recording is now skipped on release ticks.
4.13 - two Phase 3 bugs silently killing player input
(a) InputJitterBuffer.consume() advanced last_applied_seq on every tick
including a starve. Since ingest() discards seq <= last_applied_seq, one
starve on a sequence the client had not sent yet stranded the stream one
ahead of arrivals permanently - both sides advancing in lockstep, every
honest packet discarded on arrival. The client's own input_lead release is
enough to trigger it, so input died for ~30 ticks roughly every 6.5s on a
clean LAN. Now only gives up on a sequence once strictly newer data proves
it lost. Silent-client stall and ring-overflow resync are unchanged.
(b) The seq-range guard bounded incoming seq against highest_ingested_seq,
which only advances inside ingest(), which that guard gates. After a ~2s
host hitch every packet was rejected forever with no diagnostic (600+
consecutive rejections reproduced via SIGSTOP). Third iteration of this
guard; each previous version bounded against a value only the accepted
path could advance. Adds an escape after 10 consecutive rejections, which
grants an attacker nothing the rate limiter does not already bound.
(c) The transitions gate reported PASS at 3.76% while input was completely
dead, because suppression stops _record_metrics - a worse outage yields
fewer samples and a LOWER rate. Now scales the required sample count with
run length and asserts the wire's server_stalled bit. Reverting both fixes
makes it fail at samples 292/600, server_stalled=true, input_lead=12.
Fixing (a) also explained a residual the review had already traced: 151 of
151 action-marker mismatches were the server repeating a stale action on a
starve, not a prediction defect. Marker is now 0.00% in all three
conditions (was 1.7-2.5%), and free-flight p99 improved to
0.141/0.168/0.154m from 0.170/0.176/0.184m.
Two pre-existing test defects fixed alongside: the ball gate asserted
RTT-masking on a link with no RTT (flaked 2 in 5; now asserted only at
rtt >= 20ms, 5/5 under latency), and the two-bot CI compared scores across
a 3-5s window (now polls the scores the server actually held; note
score_changed is emitted only on the client path).
QA: 72 unit tests; 60s free-flight at LAN/80+-20ms/5% loss; transition
gate in all three; 2.0s and 3.5s host-freeze recovery; ball contact x5;
two-bot CI x3; all three abuse roles; net/match_net/clock/lobby smokes.
Phase 4 sign-off still pending a human playtest at ~100ms RTT - the
milestone asks how it feels, which no gate here answers.
Lands the non-networked Phase 0 tasks from multiplayer-todo.md (ship/camera/
arena refactors, sim constants, background FPS handling) plus a first pass
at exposing graphics/performance settings (presets, resolution scaling,
vsync, FPS cap, perf overlay) and a GPU profiling harness for the
real-hardware follow-up in task 0.15b.
Six rounds of reward shaping (~700M steps) failed to produce upright ground
driving. A critical review of the simulation rather than the reward found
why:
1. The hull was a 1x1x4 box with inertia (1,1,1) and no restoring torque
anywhere, so belly-down and rolled-90 were geometrically identical
resting states. "Upright" was not a physically distinguished state at
all - the reward was paying for a property the simulation did not have.
2. ~65% of episodes spawned ships via _random_position, which samples Y
uniformly over the full 18m volume (mean ~8.7m). The measured
airborne_fraction ~0.44 was largely that spawn distribution, and every
ground-handling term fades out above 3m, so the shaping being tuned
barely ever applied.
3. air_drill_chance 0.20 spawned deliberately unreachable-without-climbing
states in the stage meant to teach ground driving, and its own
air_touch_fraction (0.0002) shows the drills were never solved.
Fixes land in the physics and the task distribution, not the reward:
- ship.tscn: hull 1x1x4 -> 1.6x0.6x4 so it has one stable resting face;
inertia (1,1,1) -> (7,1,7), physically correct for the hull, making
tumbling reluctant while keeping yaw snappy.
- ship.gd: new altitude-faded righting torque (spring-damper toward
belly-down, faded out by 3m so aerials keep full attitude freedom).
This is the grav-plating analogue of Rocket League's auto-righting and
helps human pilots land cleanly too.
- training_mode.gd: new ground_start_chance branch spawning ships level and
resting on the floor with a floor-level ball - the state the handling
stage's rewards are actually written for.
- generation5.py: ground-start-chance 0.50, air-drill-chance 0.20 -> 0.0.
Reward terms are left exactly as they were; they should finally pull in a
direction the ship can go.
Retraining from scratch removes the constraint that blocked these: the
existing checkpoints in Game/bots/promoted/ no longer need byte-identical
geometry.
- Fix the goal aperture constants (were 1.85/1.65, now match
objects/goal.tscn's actual sensor exactly at 1.75/1.5) so a ball crossing
the visible edge can't fail to score.
- Cut a real navigable hole in each end wall's collision
(_build_end_wall_colliders), replacing the previous solid box — the ball
now genuinely enters the net instead of triggering the sensor a hair
before hitting a solid wall. Correct for both FLOOR and ELEVATED goal
modes via _goal_surround_bounds. A separate, slightly wider
GOAL_VISUAL_APERTURE_* pair keeps the collision hole exact while still
giving goal.gd's bezel/rim frame clearance to be seen against the hull cut.
- Resize the play volume 1.5x (INNER_HALF_X/Z/HEIGHT 12/18/12 -> 18/27/18) to
comfortably fit a 5v5 roster: updates every hand-authored literal in
arena_boundary.tscn/arena_base.tscn/the elevated arena variants that
doesn't derive from those constants, adds 5 spawn markers per team, and
rescales ship_observations.gd's normalization scales and arena_02's
cosmetic decoration/nebula-dust shader uniforms to match.
- Bake the ~170 runtime-generated CollisionShape3D nodes into the scene via
a new bake_colliders()/tools/bake_arena_boundary.gd instead of rebuilding
them on every load — a real load-time cost repeated in every parallel
headless training env. Colliders must be direct children of the
StaticBody3D to register at all, so bake_colliders() parents them onto
self and tags them with a group for idempotent re-baking, rather than
grouping them under an intermediate container node. _ready() self-heals:
it skips regenerating only when an existing bake's goal_mode metadata
matches the current one, so the FLOOR-mode bake in the shared scene is
never silently reused by an ELEVATED arena variant.
Adds a [layer_names] section to project.godot (Ships/Ball/Arena/
GoalSensor) and sets collision_layer/collision_mask on the 4 physics
body roots (Ship, Ball, Goal Area3D, ArenaBoundary StaticBody3D),
which previously all sat on the default layer 1 / mask 1 so every
body broadphase-tested against every other.
Ships collide with ships/ball/arena but no longer test against the
goal sensor; the goal's mask (Ball only) is the physics-level fix for
what goal.gd's is_in_group("ball") check was doing defensively in
code (left in place, now a no-op guard). ArenaBoundary's runtime-
generated CollisionShape3D children inherit layer/mask from the
StaticBody3D root automatically.
Verified live via godot-mcp under Jolt Physics: ship-vs-ship and
ship-vs-ball collisions still transfer momentum, the ball still
bounces off arena walls, a ball entering a goal still fires
goal_scored (score updates / HUD reset), and a ship teleported into a
goal recess produces zero overlapping bodies on the goal Area3D (was
reachable before, physics-level fix confirmed, not just the code
guard). Headless smoke test (free_play.tscn) is clean.
Hull/Canopy/EngineGlowL/EngineGlowR are runtime-baked into one ArrayMesh
in _ready via SurfaceTool.append_from, dropping 4 MeshInstance3D children
to 1 (Nose/TailFin stay separate, they're retinted per-team). Skipped in
headless mode like the goal/arena_boundary visual builds, since physics
only cares about CollisionShape3D.
All 6 source surfaces (hull, canopy, engine_l x2, engine_r x2) carry
distinct materials, so this doesn't literally cut draw calls 6 to 3 as
TODO.md assumed — Godot still issues one draw call per surface regardless
of node count. The real win is scene-tree/transform overhead, not batching.
The goal was a single flat translucent slab. Because the chase camera sits
behind the goal line at kickoff it rendered as a large blue rectangle across
the lower screen, and the hull beside the mouth was translucent field panel,
so the pocket behind it showed straight through the wall and the net appeared
a second time alongside the frame.
The boundary now carries an opaque bulkhead around each mouth, which occludes
properly. On top of that the goal becomes a pocket sunk into the wall: a dark
machined bezel lining the opening, a thin team-coloured emissive rim flush
with the wall face, and netting from a single box viewed inside-out, giving a
five-sided pocket instead of a flat panel across the back.
The net is cut with discard rather than alpha blending so it still writes
depth and sorts against the frame and the containment field like solid
geometry; a blended net would join the transparent queue and sort per object
against the boundary shell, which is the artefact this whole pass removed.
goal.tscn drops from 18 node/sub-resource blocks to 3 — it is now just the
Area3D, its CollisionShape3D and the script. All geometry is built in code
from two loops, and the mouth is measured off the collision shape rather than
restated, so the frame cannot drift from the volume that actually scores.
The sensor, its collision shape and the goal_scored signal are unchanged, and
visuals are skipped under --headless.
Every visible surface of the enclosure shared one alpha-blended material and
was drawn as several overlapping layers: floor, ceiling and four walls as
solid BoxMeshes, plus corner curves and fillets generated on top of the box
faces they eased into. Alpha-blended surfaces don't write depth and sort per
object, so the perimeter composited that tint twice and the corners three
times, giving hard-edged trapezoidal patches that re-sorted as the camera
moved. The floor box also overhung the walls by 1 m and showed through them.
Replace all of it with a single generated mesh covering the inner surface
exactly once, every piece cut to meet its neighbours edge-on and only
inward-facing triangles emitted. It carries two surfaces: an opaque hull
(deck, base fillets, goal bulkheads) and the translucent containment field
(walls, corners, ceiling fillets, ceiling).
The field shader is additive and unshaded rather than alpha-blended: additive
cannot double-darken and composites order-independently, so overlap is
structurally invisible, and being unshaded it no longer picks up per-arena
light and GI gradients across a 28x40 m panel. Fresnel replaces the old
StandardMaterial3D rim, which was a lit effect and the wrong tool. The deck
shader draws plating and field markings procedurally from the boundary's own
constants, so markings cannot drift from the collision geometry.
Per-face MeshInstance3D visibility toggling is gone; the field shader fades
facets the camera has crossed outside of per-pixel from one uniform, which is
what allows a single merged mesh.
Also adds ELEVATED goal mode and the ceiling fillets, and skips the mesh build
entirely under --headless, where training spawns instances that never render.
Collision is untouched: 166 collider shapes in FLOOR mode and 158 in ELEVATED,
verified byte-identical to before, so trained policies in Game/bots/ are
unaffected.
Ship gets a greebled hull, tapered nose, swept canopy, twin engine nacelles,
and tail fin (built via the vendored Blender MCP, generator committed at
tools/blender/gen_ship.py) in place of the 5 flat primitives. The ball is
fully remodeled as a smooth round sphere with a crossed emissive accent
pattern (gen_ball.py), replacing the old flat-shaded gold_ball rather than
just tweaking its material.
Node names (Nose/TailFin) are preserved for Ship._apply_team_color(), and
the RigidBody3D/CollisionShape3D physics on both ship.tscn and ball.tscn are
untouched so RL-trained bots and flight feel stay valid. Each part's mesh is
extracted to a standalone .res (tools/blender/extract_meshes.gd) rather than
referenced via glb::ArrayMesh_xxx sub-paths, which don't reliably resolve
across scene files and were silently rendering both models invisible.
Adds sdfgi_enabled and a ReflectionProbe to all three arenas' Environment
setup so surfaces get real bounce lighting/reflections instead of flat
ambient. Converts arena_boundary.tscn's shared glass field material from
unshaded to a shaded, rim-lit material so it reads as glass (dim face-on,
highlighted at grazing angles) rather than a flat tinted overlay.
Introduce arena_02 (Nebula) and arena_03 (Asteroid Field) alongside
arena_01, listed in a new ArenaRegistry (scripts/arena_registry.gd) as
the single source of truth for available arenas. Free Play lets the
player pick an arena from the main menu; Match/Spectate each pick one
at random per session; Training keeps its own fixed arena_01.
Nebula gets an RL-style visual treatment: a near-invisible glass
boundary material shared by all arenas, a baked equirect nebula sky
texture, a drifting-dust particle system, and a Blender-modeled
station/debris/planet decoration set. GameMode gains a
_get_arena_scene_path() hook so modes can instantiate their arena in
code instead of hardcoding it in the scene.
Until we can sort it out properly later on, for now it's a nicer testing experience to not have the player (and camera) rotating whenever they make contact with another object.
Josh Creek