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.
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.