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.
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.