Project Dalian

A modern, open-source, from-scratch C++ recreation of the Refractor 2 engine — evolving Battlefield 2's 2004 tech into a 2026-grade tactical war simulator.

Project Dalian is a clean-room reimplementation of the Refractor 2 engine that reads original Battlefield 2 data (meshes, terrain, textures, animations, level scripts) from your own game installation and renders it in a modern OpenGL pipeline — then goes well beyond the original with skeletal hit registration, physical ballistics, 6-DoF FPV drone flight, and a PBR rendering path.

It began as a fork of the excellent BattlefieldRespawn project by Rigo "Pixel" Reddig (which reverse-engineered the mesh/animation file headers), and carries that reverse-engineering work forward into a fully running engine with terrain, static geometry, collision, skinned characters, vehicles, weapons, enemy AI and drones.

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⚠️ BLEEDING-EDGE ALPHA — READ THIS FIRST

This is pre-alpha / experimental software. It is a hobby engine under very active development.

• It works, kind of. You can load real BF2 levels, walk around, shoot, drive the camera, fly a drone, and fight bots.
• It is full of bugs. Expect crashes, visual glitches, broken collision in places, half-finished features, rough animation, and things that only work on one specific map/asset.
• Test at your own risk. No warranty of any kind. It may crash, hang, or behave unexpectedly. Save your work in other apps before running it.
• APIs, file layout, controls, and behaviour will change without notice.

If that sounds fun, welcome aboard. If you need something stable, come back later.

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Legal / Assets

No EA or DICE copyrighted material is included in this repository. There are no .zip archives, textures, meshes, sounds, or any other Battlefield 2 game content committed here — only original source code written for this project (plus small, permissively-licensed third-party libraries and a tiny hand-authored cube used to test the mesh parser).

Project Dalian requires a legitimate installation of Battlefield 2 (or a compatible mod such as Project Reality). At runtime the engine reads assets directly out of your local BF2 archives. You must own the game. This project is not affiliated with or endorsed by EA or DICE. "Battlefield" is a trademark of its respective owner.

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What works today

Launcher & UI:

• Main menu with map browser (scans your BF2 install), options, multiplayer tab, and quit — no command-line args required to start
• BF2-style loading screen — progress bar with phase text while archives load; Before the First Volley plays during load only; Ready button lets you listen to the full track before deployment opens
• Resolution-agnostic UI — all menus/HUD layout in a fixed 1600×900 design space with uniform scaling and letterboxing; long text clips instead of overlapping
• Dynamic resolution list from SDL (includes desktop ultrawide modes)
• Settings persistence (%APPDATA%\ProjectDalian\ProjectDalian\settings.cfg): video, graphics, audio, BF2 install path, player name, rebindable controls
• Display recovery hotkeys: Alt+Enter toggle windowed/borderless, F11 cycle modes, Ctrl+Shift+W safe windowed 1920×1080; launch with --windowed or BF2_WINDOWED=1 if stuck in bad fullscreen
• Resolution changes apply immediately — Options → Video → Apply updates the GL viewport without needing Alt+Enter

Multiplayer (alpha):

• Host/join flow with faction picker, ready states, and lobby start
• Tailscale server browser — host advertises on create; joiners auto-scan 100.x/24
• LAN server browser + optional Tailscale subnet scan
• Late-join support (configurable)
• Session discovery/advertising over UDP
• MP ticket grace — bleed paused until 2 humans deployed or 90s elapse
• Kill feed — top-right kill toasts with retail BF2 bot names; join/leave toasts for human players
• Improved position/yaw sync for remote players
• Auto round restart — 12s countdown after victory, then deploy again

Asset pipeline (verified byte-for-byte against retail BF2 assets):

• .staticmesh, .bundledmesh, .skinnedmesh loaders (multi-geometry / multi-LOD)
• .ske skeleton + .baf animation loaders and hierarchy evaluation
• .collisionmesh (cols / faces / verts / BSP)
• .dds textures (DXT1/DXT3/DXT5)
• Zip archive mounting (miniz / DEFLATE) — a small virtual file system
• .con / .tweak interpreter (templates, activeSafe, object placement)
• 16-bit heightmap terrain + StaticObjects.con placement resolution

Rendering:

• Terrain colormap + detail splatting with a shared-detail blend

• Static geometry with BF2 material layers: _c base, _de detail, _deb normal map, _di dirt (tiling break), _cr crack decal

• Baked per-object lightmaps (UV5 / Lightmaps/Objects atlases)

• Water plane (Fresnel + specular glint), gradient sky, sun, distance fog

• Undergrowth / grass billboards with wind sway

• GPU skinning (bone-matrix palette evaluated in the vertex shader)

• PBR surface path (Cook-Torrance GGX; albedo from _c+_de, synthetic roughness from detail-normal intensity)

• Cascaded Shadow Maps depth pass (render occluders to a shadow array, sampled with PCF in the surface shader)

• Offscreen-FBO post-process pass (used for the FPV drone feed)

• Vehicle geometry assembly from .con hierarchy (hull + child parts such as rotors); internal geometry parts (wheels, turrets, landing gear) positioned via geometryPart indices baked from bundledmesh BLENDINDICES

• Helicopter rotor blur (static blades at low RPM → blur disc at speed)

• Landing gear tuck animation on jets (gear struts, hatches, wheels split from hull mesh and rotated from .con LandingGear data)

Level / map fidelity (Dalian Plant and compatible maps):

• 3×3 secondary heightmap cluster — samples neighbouring HeightmapSecondary_* patches so props and vehicles sit on decks/ramps instead of bare primary terrain
• Overgrowth trees — Overgrowth.raw instancing for distant tree/bush cover
• Compiled roads — CompiledRoads.con spline data for road-aligned placement
• Texture parent-folder resolve — finds DDS colour maps when BF2 stores them one directory up (fixes purple/missing materials on pipes, etc.)
• Template resolver — nested .tweak / .con runs for multi-part statics
• DummyObjects.con merge — decorative props referenced only from dummy lists
• Asset audit on load — optional BF2_TEXAUDIT=1 reports missing textures
• Cheaper water shader — distance fade, fewer waves, skips work when high above the surface
• Boat buoyancy — sea vehicles float at the water plane instead of driving the seabed

Combat & vehicles (v0.5.0-alpha):

• Vehicle weapon profiles — heli minigun/rockets, tank main gun from retail vehicle .tweak
• Distinct missiles — SAM vs AT/RPG projectile templates (igla, at_predator, insgr_rpg)
• Handheld depth — deviation ramp, burst fire, e_bhit_* impacts, tweak addTemplate chains
• AI kit weapons — defenders use retail rifle fire rate/damage/spread
• Placement audit — placement_audit tool flags floating/embedded props (docs/PARITY.md)
• Collision — bundledmesh + compiled-road collision; soldier+vehicle col merge; render-mesh fallback for roads/bridges

See docs/PARITY.md for the full gap list (afterburner particles, jet tuning, multiplayer, conquest, static prop heights, etc.).

Audio (SDL_mixer, reads retail BF2 archives):

• Weapon fire / reload / deploy sounds parsed from weapon .tweak files
• Voice lines from VoiceMessages*.con (reload, grenade, out-of-ammo, etc.)
• Level ambient loop from AmbientObjects.con
• Menu music: The Siege of Dalian (main menu); Before the First Volley (loading only)
• Bundled OGG/MP3 under apps/dalian/assets/music/ or your Downloads/ folder
• Vehicle engine / tire sounds parsed from vehicle .tweak (loops on enter, volume follows throttle/speed) — coverage depends on per-vehicle tweak data

Simulation / gameplay:

• Deploy screen (Enter): kit picker, faction selection, spawn point map
• Vehicle entry/exit (E), multi-seat crew switching (F1–F8)
• Ground vehicles: throttle, steering, terrain-following chassis tilt, wheel spin/steer on separated geometry parts where .con defines wheel geometry
• Helicopters: BF2-style collective (W/S), yaw (A/D), mouse cyclic pitch/roll, rotor spool RPM, AI gunner seat, flares (X)
• Fixed-wing jets (alpha): BF2-inspired arcade flight with body-wing lift, engine spool before runway roll, V1 rotation (~72 km/h), double-tap W or Ctrl afterburner (sprint fuel + 1.6× thrust), G landing-gear stow with tuck animation, mouse pitch/roll, rudder (A/D), horizon damping
• Conquest layer (alpha): tickets, control points, capture logic, voice cues
• Modular game sim — game_sim.cpp + .inl shards (vehicles, missiles, interaction, conquest) with net-ready snapshot types
• In-game pause menu (Esc): resume, options, leave to main menu
• Character controller with bilinear terrain following and object collision
• First- and third-person camera, animated player soldier + held weapon
• Weapon switching (Q or mouse wheel), automatic fire, muzzle flash, recoil
• Two hit-registration models, hot-swappable (F):
  • Hitscan raycast
  • Physical projectiles with gravity + quadratic air drag + wind deflection
• Skeletal capsule colliders mapped to individual animated bones (head / torso / limbs) for per-zone hit detection instead of one big box
• Enemy AI spread across map objectives: idle patrol, advance-to-contact when spotted, reaction delay, burst fire, limited simultaneous attackers, player health regen (tuned to be survivable, not an instant-death swarm)
• 6-DoF FPV recon drone (F9 to toggle): true rigid-body quad with independent per-rotor thrust, gravity, and simulated battery voltage sag, plus a render-to-texture FPV feed with signal degradation
• FPV kamikaze loitering munition (F10): a one-way, player-steered terminal munition using a lighter/faster airframe. FPV link with faster signal decay; detonates on impact (terrain, buildings, enemies), manual trigger (LMB/Space), or dead battery. No recall.
• Car-launched SAM (F8): opens a tactical map; click a destination anywhere on the map. The Igla launches from the nearest ground vehicle roof with a lofted climb so you can watch it fly. Uses retail BF2 igla_9k38 mesh plus e_missile_ignition / e_missile_trail / e_vexp_igla effect bundles when present. AT rockets use RMB on the Anti-Tank kit.

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Download (Windows, pre-built)

No compile required — grab the latest release from GitHub Releases.

1. Download ProjectDalian-*-win64.zip
2. Unzip anywhere
3. Run project_dalian.exe
4. Point Options → BF2 path at your retail install (C:\Program Files (x86)\Battlefield2)

The zip contains only Project Dalian binaries, SDL2 runtime DLLs, and bundled menu music/art. No EA/DICE game data — you must own Battlefield 2.

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Build from source

Requirements:

• CMake 3.24+
• A C++20 compiler (MSVC 2022, Clang, or GCC/MinGW-w64)
• Git (dependencies are fetched at configure time)

cd C:\Projects\bf2respawn
cmake --preset default
cmake --build build
ctest --test-dir build      # optional: run parser unit tests

Third-party libraries used: SDL2, SDL_mixer, GLM, Dear ImGui, GLEW, miniz, stb. Small vendored copies (GLEW / miniz / stb) live under third_party/ and are permissively licensed. On Windows, SDL2.dll and SDL2_mixer.dll are copied next to project_dalian.exe at build time.

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Run

Quick start (main menu)

Build, then launch with no arguments. The main menu scans maps under your BF2 install (set the path in Options if auto-detect fails):

.\build\apps\dalian\project_dalian.exe

Recovery if display settings break the UI:

.\build\apps\dalian\project_dalian.exe --windowed
# or delete/edit %APPDATA%\ProjectDalian\ProjectDalian\settings.cfg

Loading music: place Before_the_First_Volley.mp3 in your Downloads folder, or set BF2_LOADING_MUSIC=C:\path\to\track.mp3. Skip the Ready gate in automation with BF2_SKIP_LOADING_READY=1.

Direct map load (legacy / headless)

Point the app at a BF2 level archive plus your Objects_client.zip:

$bf2 = "C:\Program Files (x86)\Battlefield2\mods\bf2"

.\build\apps\dalian\project_dalian.exe `
    "$bf2\Levels\Dalian_plant\server.zip" `
    "$bf2\Objects_client.zip"

Settings and the BF2 root path from the main menu are stored under %APPDATA%\ProjectDalian\ProjectDalian\settings.cfg.

Controls

Input	Action
Menu
Alt+Enter	Toggle windowed / borderless
F11	Cycle windowed → borderless → exclusive
Ctrl+Shift+W	Safe windowed 1920×1080 (display recovery)
Loading
Ready button / Enter / Space	Continue to deploy after map load
On foot
W A S D	Move
Shift	Sprint
Space	Jump
Mouse	Look
Tab	Toggle mouse capture
LMB	Fire (hold for automatic)
RMB	AT rocket (Anti-Tank kit) / vehicle secondary
Mouse wheel	Cycle weapon
R	Reload
4 / 5 / X	Grenade / place C4 / detonate C4 (or vehicle flares)
F8	Open car-SAM map (near a ground vehicle); click destination to fire
F9	Launch / recall FPV recon drone
F10	Launch FPV kamikaze loitering munition (one-way)
H	Medkit self-heal (Medic kit)
C	Toggle 1st / 3rd person
E	Enter / exit vehicle
Enter	Deploy screen (kit, faction, spawn)
Esc	Pause menu (in-game) / back (deploy)
Helicopter (pilot)
W / S	Collective up / down
A / D	Yaw
Mouse	Cyclic pitch / roll
X	Flares
F1–F8	Switch crew seat
Jet (pilot)
W / S	Throttle / brake
A / D	Rudder
Mouse pull back	Pitch up (rotate on runway / climb in air)
Mouse left/right	Bank (in air)
Double-tap W or Ctrl	Toggle afterburner (sprint fuel)
G	Stow / deploy landing gear
F1–F8	Switch crew seat
Drone
W/S throttle, A/D yaw, mouse pitch/roll	Fly the quad

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Tools

Headless, windowless utilities for inspecting and rendering assets straight from a retail archive (great for debugging the loaders):

• meshinfo — dump mesh header / geometry / material info
• assetprobe — load any asset (mesh / ske / baf / collisionmesh / dds / con / tweak) directly out of an archive and print stats
• bf2snapshot — offscreen renderer: render a mesh, a skinned+posed character, a level's terrain, or a full assembled level to a PNG with no window

$zip = "C:\Program Files (x86)\Battlefield2\mods\bf2\Objects_client.zip"
$lvl = "C:\Program Files (x86)\Battlefield2\mods\bf2\Levels\Dalian_plant\server.zip"

.\build\tools\meshinfo\meshinfo.exe tests\fixtures\cube.staticmesh
.\build\tools\snapshot\bf2snapshot.exe --level $lvl level.png 1100

The main app also supports a scripted headless capture: project_dalian.exe <level.zip> <objects.zip> --shot out.png [frames] [--tp] [--drone].

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Architecture

engine/
  formats/   mesh, animation, archive, collision, dds, terrain loaders
  core/      level loader, resource manager, scene graph, template resolver,
             atmosphere, object lightmaps, undergrowth
  anim/      skeleton posing + CPU/GPU skinning (bone-matrix palette)
  render/    OpenGL renderer, PBR + shadow shaders, cascaded shadow maps,
             texture cache
  physics/   physics world, character controller, 6-DoF drone, missile flight,
             kamikaze loitering munition
  script/    .con/.tweak interpreter + gameplay script sandbox
  net/       UDP lobby protocol, player sync, server discovery hooks
apps/
  dalian/    war-sim client: main menu, deploy UI, multiplayer lobby, game audio,
             settings, factions — see apps/dalian/*.cpp
  viewer/    SDL2 + ImGui mesh/skeleton/animation viewer
  sandbox/   physics/gameplay/network smoke test
tools/       meshinfo, assetprobe, snapshot (headless renderer)
tests/       parser unit tests + hand-authored fixtures
docs/        file-format reverse-engineering notes

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Roadmap status

• Phase 0 — project foundation, mesh loader, meshinfo CLI ✔
• Phase 1 — zip archive mount, DDS loader, full geometry extraction, tests ✔
• Phase 2 — OpenGL viewer + ImGui browser + headless PNG snapshot ✔
• Phase 3 — .ske/.baf loaders, skeleton eval, CPU + GPU skinning ✔
• Phase 4 — .con/.tweak interpreter (templates, placements) ✔
• Phase 5 — heightmap terrain + static object placement + level assembly ✔
• Phase 6 — physics world + .collisionmesh + character controller ✔
• Phase 7 — gameplay script sandbox ✔
• War-sim layer — skeletal capsule hitboxes, physical ballistics, 6-DoF FPV drones, vehicle-launched guided/ballistic missiles, PBR + cascaded shadow maps, enemy AI ✔ (rough / alpha)
• War-sim layer (2026 sprint) — main menu + map browser, settings/options, resolution-agnostic UI, deploy screen + factions, vehicle entry/driving, helicopter flight, wheel animation split, BF2 weapon/voice/ambient audio, vehicle engine sounds (partial), multiplayer lobby + LAN/Tailscale browser ✔ (alpha / incomplete)
• In progress — jet polish (per-aircraft gear/exhaust), animation retargeting, full vehicle audio coverage, networking hardening, particle effects (afterburner flames), in-engine editor
• Next — more munitions, radio comms, live volume sliders, dedicated server polish, envmaps / extended terrain mesh

Recent implementation notes (Jul 2026)

Area	Status
Loading screen	Progress bar, loading music, Ready gate before deploy
Main menu / options / pause	Working; UI scales to any resolution
Display / fullscreen	Dynamic mode list; resolution Apply refreshes viewport instantly
Multiplayer lobby	Host/join/ready/start; LAN + Tailscale discovery
Multiplayer in-match	Ticket grace, teammate minimap dots, round auto-restart
Deploy UI	Faction, kit, spawn map
BF2 controls	Retail defaults, rebindable Options tab, crouch/prone, scoreboard
Map fidelity	Heightmap cluster, overgrowth, roads, texture resolve, asset audit
Ground vehicles	Drive, terrain tilt, animated wheels (where meshed)
Boats / RHIBs	Water-surface buoyancy
Helicopters	Collective/yaw/cyclic, rotor RPM blur, AI gunner, flares
Jets	Spool, V1 rotate, body-wing lift, afterburner, gear tuck (G) — alpha
Game audio	Weapons, voice, ambient; vehicle loops on enter
Conquest	Tickets, CP capture, voice cues — alpha
Crash fix	SDL2 + SDL2_mixer DLLs copied next to exe on build

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Attribution

• Mesh / animation file-format reverse engineering originally by Rigo "Pixel" Reddig — BattlefieldRespawn.
• Everything in this repository is original code released under the MIT License (see LICENSE), except the vendored third-party libraries under third_party/, which retain their own permissive licenses.

Battlefield 2 and the Refractor engine are the property of EA / DICE. This is an independent, non-commercial, clean-room engine project and ships none of their content.