GT3 Revisited

GT3 Revisited

An open-source reimplementation of the Gran Turismo 3 A-Spec engine for modern platforms: Windows, macOS, Linux, Android, iOS and Meta Quest (VR).

GT3 Revisited contains no game data or assets. It needs a disc image (.iso) that you made from your own copy of the game. At runtime it reads the image directly and decodes the assets. Nothing is extracted to disk or redistributed.

Status: the whole game is playable. Everything in the original is implemented: GT Mode (dealers, garage, tuning, licenses, championships, endurance races with pit stops, endings), Arcade (single race, time trial, free run, 2-player split screen), AI opponents, replays with the TV cameras, the Replay Theater and Analyzer, movies, music and sound, all from your disc. The physics is verified against the original. The remaining differences are small and listed below.

What you get

The game	GT Mode, Arcade, licenses, 2P battle, Replay Theater, Options: the game's own menus, text (every language on the disc), fonts, movies and soundtrack
Faithful racing	physics, AI, cameras, HUD, replays, lighting, reflections, smoke and sounds reimplemented from the original's behaviour and compared side by side with it
Online battle	the arcade's i.LINK Battle rebuilt for the internet and LANs: up to 6 players, session codes, no port forwarding
Quick race	any of the game's events with any car, nothing to unlock
Saves	any number of named saves; import from and export to the PS2 original
Modern display	any resolution and aspect ratio, widescreen, high refresh rates (or a 60 fps limit), MSAA, dynamic resolution, or the original 640×448 look
VR	Meta Quest: the menus on a large virtual screen, races in stereo from the driver's seat, Touch controllers (sticks and analog triggers, or grab a steering wheel)
Controllers	keyboard, any gamepad, wheels and pedals, all remappable; analog pressure buttons, DualSense adaptive triggers, Xbox impulse triggers, wheel force feedback, tilt steering, touch controls on phones and tablets (move, resize or hide each one)
Mods	replace any game file, add music, add new cars (electric ones too) to the dealers

How it's built

GT3 Revisited is an independent reimplementation. The disc's file formats are documented in FORMATS and docs/formats/, and how the game behaves is described per system in docs/behaviour/ (physics, AI, GT Mode, menus, race presentation, sound, music), with implementation notes in docs/dev/. It is verified against the original, side by side and with automated tests. It contains no game data or assets; all game content is read from your own disc at runtime. The rules for contributions are in CONTRIBUTING.

Installing

Download the package for your system from the Releases page. Each release lists SHA256SUMS, and every file carries a build attestation: gh attestation verify <file> --repo matt-pulsipher/GT3-revisited checks that it was built by this repository's workflow from the tagged source. The packages are not signed with a developer certificate, so the first launch needs one extra step:

• Windows: unzip and run gt3r.exe. If SmartScreen says "Windows protected your PC", choose More info → Run anyway. 3D runs on Vulkan, or on GPUs without it (e.g. GeForce 400/500, Intel HD 2000–4000) on OpenGL ES through ANGLE, which the package includes.
• macOS (Apple Silicon, macOS 12 or later): unzip and move gt3r.app to Applications. On the first launch macOS says it cannot verify the app; open System Settings → Privacy & Security, scroll down and choose Open Anyway next to GT3 Revisited. Later launches open normally.
• Linux (x86_64): extract the archive and run gt3r. 3D needs a Vulkan driver (Mesa's mesa-vulkan-drivers on AMD / Intel, or your GPU vendor's), or on older GPUs without Vulkan, OpenGL ES 3.0 (Mesa, or NVIDIA's legacy drivers).
• Android (7.0 or later, arm64 or x86_64): open the .apk on the device and allow installing from that source when asked. In countries where Android requires verified developers for sideloaded apps, use Android's advanced install flow for unverified apps (Developer options) or install with adb install gt3r-android.apk.
• Meta Quest (verified on Quest 3; Quest 2, 3S and Pro untested): turn on developer mode for the headset in the Meta Horizon phone app, then install gt3r-quest.apk from a computer with adb install gt3r-quest.apk (or SideQuest / Meta Quest Developer Hub). Copy your disc image into the headset's Download folder over USB. The game is in the library under Unknown Sources. Details: VR.
• iPhone and iPad (iOS 16 or later): there is no package, because an iOS app has to be signed for the device it runs on. Build it on a Mac and install it with Xcode and your own Apple ID; a free account is enough (Building). With a free account the installed app stops opening after 7 days: installing it again renews it, and your saves and settings stay.

Direct links to the newest release, always the same: gt3r-windows-x64.zip, gt3r-macos-arm64.zip, gt3r-linux-x86_64.tar.gz, gt3r-android.apk, gt3r-quest.apk. The game's Download update uses them.

Or build it yourself (Building); a build from source needs none of the steps above.

Running

You need a disc image of Gran Turismo 3 A-Spec. The NTSC-U releases (SCUS-97102 and the PBPX-95503 bundle disc) are verified; other regions are untested (COMPATIBILITY). Only .iso images are read.

gt3r                                  # first run asks for your disc image

gt3r "/path/to/Gran Turismo 3.iso"    # or pass it directly

You can also drag the .iso onto the window. On Android and the Quest, choose Open disc image and pick the file (android/README.md). On iOS, Open disc image shows the Files app's picker: the image can be anywhere it reaches (On My iPhone, a network share, another app's folder) and is read where it is, never copied. The path is remembered, with the last five discs you opened. If the remembered disc is missing at startup (moved, or on a drive that isn't connected), the first screen says which file failed and offers the recent discs that still exist.

The game starts like GT3: the opening movie (skip with Cross/Start), then the title menu. Press Select on the title menu, or click/tap the GT3R menu button beside it, to reach GT3 Revisited's main menu underneath the game:

Main menu
Play	back to the game (opening movie, then the title menu)
Online battle	race other players over the internet or a LAN
Settings	display, audio, controls, force feedback, touch, disc, online
Mods	enable or disable installed mods
Music jukebox	the soundtrack from your disc
Quick race	any event with any car
Time trial	any car on any course; saved replays
Movie theater	the game's movies
Car database	specs, torque curves, upgrades and events
Save editor	change a GT Mode save (below)
Change disc image...	recent discs, or browse
Developer options	asset browser, viewers and test screens for working on the project
Quit

Keys: F11 toggles fullscreen and F12 saves a screenshot to screenshots/ in the user data folder.

User data folder

Settings, saves, replays, mods and screenshots live in:

• Windows: %APPDATA%\GT3Revisited\GT3Revisited\
• macOS: ~/Library/Application Support/GT3Revisited/GT3Revisited/
• Linux: ~/.local/share/GT3Revisited/GT3Revisited/
• Android: the app's private storage, shown in the Files app as GT3 Revisited (the Mods screen's Open folder goes there)
• iOS: the app's Documents, shown in the Files app as On My iPhone › GT3 Revisited and in Finder when the device is connected (the Mods screen's Open folder goes there); a copy of the disc image can go there too

If a portable.ini file sits next to the executable, all user data is kept beside it instead.

In the folder
config.ini	settings (below)
saves/	GT Mode saves (below)
replays/	saved replays (.gt3replay), listed by the Replay Theater and Time trial
mods/	installed mods (MODDING)
screenshots/	F12 screenshots

Settings

Settings (main menu, the first-run screen, or --screen settings) edits everything with a pad, keyboard, mouse or touch: Up/Down picks an option, Left/Right changes it, Cross toggles or opens, Triangle/Esc goes back, L1/R1 or Tab switches page. Changes are saved immediately; all but the 3D renderer switch apply at once. The game's own Options menu (title menu) works as in the original. config.ini can also be edited by hand; keys marked (file) are only there:

Section / key	Values
[game] disc	path	disc opened at startup
[game] recent1..recent5	paths	recently opened discs, newest first
[app] start	game / hub	start with the game, or in Developer options
[video] fullscreen	on / off	desktop window mode (F11)
[video] aspect	16:9 / 4:3 / fill	the game's picture: 16:9 (default), 4:3 like on a 4:3 TV, or the whole screen (races use its full width; menus and movies stay 4:3)
[video] vsync	1 / 0	wait for the display refresh
[video] limit_60fps	on / off	on 120 Hz and faster displays, draw about 60 frames a second (every Nth refresh)
[video] msaa	1 2 4 8	3D anti-aliasing (clamped to the GPU); default 4, 2 on phones, tablets and the Quest (Android, iOS)
[video] anisotropy	1 2 4 8 16	anisotropic texture filtering (1 = off); default 4
[video] render_scale	auto, 0.5..4.0	3D resolution vs. the screen; above 1.0 the 3D views render larger and are scaled down (supersampling), up to 16384 pixels a side
[video] dynamic_resolution	on / off	lower the 3D resolution (to 50% at most) when the GPU can't keep up and raise it while it keeps up, up to render_scale; with auto, up to the screen's full resolution (at most 1440 lines), starting where the last race ended (kept in dynamic_start). Default on for phones and tablets
[video] full_car_detail	on / off	every car in full detail at any distance; off: distant cars switch to GT3's simpler models. Default on, off for phones and tablets
[video] gpu	auto / gles / gles_driver / 0	the 3D renderer: auto = SDL_GPU (Vulkan, Metal), or OpenGL ES where the GPU has no Vulkan (Windows, Linux); gles = OpenGL ES first; gles_driver = the same on Windows with the graphics driver's OpenGL ES rather than ANGLE; 0 = 2D-only (restart required). Settings offers only the kinds of OpenGL ES that open on the computer
[video] original_res	on / off	(file) races at the PS2's 640×448 in a 4:3 frame
[video] original_filter	nearest / bilinear	(file) upscaling filter for original_res
[video] car_reflections, car_shadows	on / off	(file)
[audio] device	device name	output device (Windows, macOS, Linux); absent: the system default. A device that isn't connected plays on the default until it is
[audio] music_volume, sfx_volume	0.0..1.0
[audio] surround_cue	on / off	GT3's rear-channel phase cue for Pro Logic decoders
[race] views	all / gt3	race views: GT3's plus bumper without mirror and far chase, or GT3's only
[race] camera_shake	on / off	GT3's in-car vibration
[race] units	kmh / mph	speed unit in races and menus (absent: the disc's, mph on the North American disc, km/h on the European and Japanese ones)
[race] split	auto / horizontal / vertical	(file) 2P split (default: as GT3)
[race] analog_response	linear / original	sticks, triggers, wheels, touch and tilt: a linear response (default) or GT3's DualShock 2 curves (Settings → Controls)
[input] background	on / off	desktop: controllers and wheels keep driving the game while another window is in front, e.g. on a second monitor (default off; Settings → Controls). The keyboard works only in the game's window
[player1], [player2]	controller (auto, a device name, or keyboard), keyboard, race, rumble (auto, modern, gt3); phone_vibration (player 1, Android)	see INPUT
[ffb]	see INPUT	DualSense/Xbox triggers and wheel force feedback
[touch]	see INPUT	on-screen controls on phones and tablets; Customize layout moves, resizes and hides each one
[online] server	host name	relay server (default gt3r.gameversions.com; set in the lobby)
[online] update_check	on / off	ask the relay server for a newer version at startup (Settings → Online)
[options]		the game's own Options menu (set in game)
[mods]		see MODDING

Saves

GT Mode keeps any number of saves in saves/ (no memory cards). The title menu's Load game / Save game / File Operation pages list them by name, with day, credits, cars and completion, and let you start a new game, save under a new name or over a save, rename, copy and delete. The game being played autosaves after every race and continues at the next launch. A save that cannot be read (damaged, or from a newer version) is never written over.

Save editor (main menu) changes a save of the disc's region: credits, prize money, the day, races and wins, the endings seen; the garage (add any car of the game in any paint, remove a car, choose the active car, set a car's paint, odometer, engine, oil and dirt); each license test's medal; each race's best place and the championships won; the arcade's courses and car levels. Numbers change with Left/Right or a number pad (keyboard digits work too). Nothing is written until Save (Start); leaving with changes asks first. The game being played takes the changes at once. Medals, results and cars are set as chosen: the prize cars they would have won are not given.

Saves from and to the PS2 original: on the Load game and File Operation pages, "FROM A FILE" imports a save from anywhere (a GT3 Revisited .sav or a PS2 save), and "Export to PS2" in a save's menu asks for the format: a .psu, a PCSX2 .ps2 card image or a raw save (.raw), then where to put it. The raw save is the bare game data file that save editors such as GT3SaveEditor open; an edited one imports like any other save. Home → Trade and the arcade's Load Garage take a friend's save the same way. Each release of the original reads only its own save, and saves go to and from your disc's: BASCUS-97102GAMEDATA (NTSC-U, both discs), BESCES-50294GAMEDATA (PAL) or BISCPS-15009GAMEDATA (NTSC-J). gt3tool converts on the command line too (it needs your disc for the game data):

gt3tool save-import <iso> <ps2 save> <saves folder>/name.sav
gt3tool save-export <iso> <saves folder>/name.sav <out.psu | out.ps2 | out.raw | out folder> [--lang=XX]

On a PAL disc, --lang picks the language the original starts in with the exported save: BR (British English, the default), FR, GR, IT or SP.

<ps2 save> can be the data file (BASCUS-97102GAMEDATA etc., under any name, e.g. a .raw), its save folder, a PCSX2 folder memory card, a .psu (uLaunchELF / EMS export) or a PCSX2 .ps2 / .mcd card image (8 MB, read only). The export writes a .psu, a new 8 MB .ps2 card image holding just this save, the data file alone (.raw) or a folder <out>/BASCUS-97102GAMEDATA/ (or the PAL / NTSC-J name). To move a save onto a PCSX2 card you already use, import the .psu with a memory-card manager. Compressed .max / .cbs saves (Action Replay, CodeBreaker) are not read; convert them to .psu first.

Carried over: credits, days, races / wins, prize money, the garage (parts, settings, paint, wheel, odometer, oil, dirt), the wheel inventory, license medals and best times, race results, prizes, trophies, arcade progress, time-trial records (arcade and per course), machine-test rankings and the last name entered for a record. Setting files on the card and a championship saved between rounds are not carried. Keep a copy of your card before writing to it. Details: GT_MODE.

Online

Online battle (main menu, or Arcade → i.LINK Battle) races up to six players, each on their own machine:

• Create a session shows a code such as ABCD-EFGH; the others choose Join with a code and type it. No port forwarding is needed: players connect directly where they can, and otherwise through the relay server, gt3r.gameversions.com by default (UDP 47631). Another server can be set under Relay server in the lobby.
• Host by address / Join by address works without any server, on a LAN or with UDP port 47630 forwarded to the host.
• Every car of the game can race, none locked: chosen by maker, by class, or from your GT Mode garage. The classes are the arcade's C, B, A, S and rally cars: its class lists' cars (raced as the arcade does), and every other car by its weight per power, as GT3 classes garage cars.
• The host's Car rules limit the cars: class, production or race cars, drivetrain, NA or turbo, stock cars only, a power limit, mod cars. The car page can list only the cars allowed.
• Every lobby page works with a mouse, touch or a VR controller's pointer too.
• Mod cars are offered to the other players as checked downloads.
• The other players can see your IP address, as in any peer-to-peer game.
• Updates. At startup the game asks the relay server whether a newer version exists. That is one small message with the game's version and platform (Windows, macOS, Linux, Android or other), nothing else.
  • When a newer version exists, a dialog says so once per version: Download update downloads the package for your system, Later keeps playing, and Release notes opens the release page. A badge in the main menu's title bar opens it again.
  • Sessions through the relay server need an up-to-date game. An older one shows "Update required to play online" when you open Online battle.
  • Offline play is never blocked. Host / Join by address needs the same version on both machines.
  • Turn the startup check off under Settings → Online ("Check for updates at startup", or [online] update_check = off). Check now there asks on demand; Download update and Release notes are there too.

How it works, and how to run your own relay: ONLINE.

Mods

The Mods screen installs mods from a .zip (Install from .zip, or drop the .zip onto the window on a computer), turns them on and off, and removes them. Mods live in mods/ in the user data folder; Open folder opens it (on Android and iOS, in the Files app). A mod can replace any file of the game, add music, or add cars, defined in small text files, that appear at the dea