0herculabs/hl360-forza3

A work-in-progress static recompilation of Forza Motorsport 3: Ultimate Collection that runs natively on Windows PCs. The Xbox 360 PowerPC code is translated to C++ using the ReXGlue SDK, while the runtime provides the console services required by the game, including graphics, audio, input, profiles, file-system access, and downloadable content.

The project includes its own launcher for installing and verifying both game discs, managing local profiles, configuring the port, and installing Project Forza Plus 3.

The only version currently supported is Forza Motorsport 3: Ultimate Collection (USA), Title ID 4D53084D, Media ID 6F74359D, with default.xex version 0.0.0.8.

Development and testing are performed with the following exact disc images:

The MD5 values are provided only to identify the correct disc dumps; they are not intended as cryptographic guarantees. After extracting Disc 1, the launcher also verifies every installed file against game_files.sha256 using SHA-256. Other regions, editions, or revisions may contain a different executable and are not currently supported.

The launcher is based on the one created for the Forza Motorsport 2 recompilation and uses SDL3, SDL_GPU, and Dear ImGui. Its interface is available in English and Spanish. On first launch it follows the operating-system language, and it can be changed at any time with the EN/ES selector.

Profiles	Graphics

Project Forza Plus 3	Installation and verification

• Two-disc installation: the launcher automatically identifies each ISO and guides you through the process.
  1. Disc 1 — Play Disc: extracts approximately 7 GB of game data, excluding $SystemUpdate, and verifies every file against the SHA-256 manifest.
  2. Disc 2 — Content Install Disc: extracts all eight car and track content packages. fm3tool install-dlc installs them, including their licence headers, in the format expected by the game.
• Local profiles: create, select, and remove named profiles. Each profile has its own offline XUID and separate save directory under user\<XUID>\.... Deleted profiles are preserved in user\deleted-profiles\.
• Graphics: windowed or fullscreen mode, monitor selection, window size, 16:9 output, 720p/1440p/4K presets, 1×–4× internal resolution, anisotropic filtering, FXAA, and Bilinear, AMD CAS, or AMD FSR scaling.
• Controls: Xbox and other SDL/XInput-compatible controllers, remappable keyboard controls, and optional mouse input mapped to the right stick.
• Language and audio: select the in-game language or mute game audio.
• Project Forza Plus 3: install, update, configure, and remove the mod from its ZIP archives. Available options include Career mode selection, harder AI, and field of view.
• Shader precompilation: prepares graphics pipelines before play to reduce first-time stutter.

Direct3D 12 and readback_resolve = "fast" are selected automatically. FM3 requires render readback for the road surface and vehicle thumbnails, while the synchronous full mode limits the game to 30 FPS. These settings are therefore not exposed in the launcher.

Project Forza Plus 3 supplies an alternative set of 18 content packages. During installation, the launcher safely backs up the eight Ultimate Collection packages and replaces them with the modded set. Removing the mod restores the original packages.

Project Forza Plus 3 has longer paths than the original Disc 2. Its v1.3 ZIP requires a user-data root of at most 53 characters for the longest packaged file. Use short folders such as C:\FM3\game and C:\FM3\user. The launcher checks the actual mod archive paths before changing an existing installation. To relocate existing user data, close the game and launcher, copy the entire user folder to the shorter location, then select that folder under Install > Change user data folder. Keep the old copy until the game and saves have been checked.

• Windows 10 or Windows 11, x64
• Visual Studio 2022 Build Tools with MSVC and the Windows SDK
• LLVM/Clang 20 or newer (winget install LLVM.LLVM)
• CMake 3.25 or newer
• Ninja
• Git for Windows, with sh available on PATH

Clone the repository together with its submodules:

git clone --recursive https://github.com/0herculabs/hl360-forza3.git
cd hl360-forza3

Build the SDK once, then build the game, launcher, and supporting tools:

Before building the game, extract your supported Disc 1 into game/disc1/; game/disc1/default.xex is required to generate the recompiled sources. After building the SDK you can use its extraction helper as follows:

scripts\build_sdk.cmd
:: Build just the extraction helper; this does not require generated game code.
cmake --preset win-amd64-release -DCMAKE_PREFIX_PATH="%CD%\thirdparty\rexglue-sdk\out\install\win-amd64"
cmake --build --preset win-amd64-release --target fm3tool
scripts\install_game.cmd "C:\path\Disc 1.iso"

Run the CMake commands from a terminal with scripts\devenv.cmd loaded.

:: Apply patches\sdk\*.patch and install the SDK into out\install
scripts\build_sdk.cmd

:: Build the game, launcher, and tools into out\build\win-amd64-release
scripts\build.cmd release

scripts\devenv.cmd loads the MSVC environment and places Clang from C:\Program Files\LLVM\bin at the beginning of PATH.

Recompiled code is generated in generated\default\ from fm3_manifest.toml and config\*.toml. The build system automatically runs the code generator again whenever one of those inputs changes.

The launcher also provides non-interactive modes that use the same internal installation and verification paths as the graphical interface:

fm3-launcher --import-iso <iso> --game-dir <dir> --user-dir <dir> [--log <file>]
fm3-launcher --verify --game-dir <dir> [--log <file>]
fm3-launcher --screenshot <file.bmp> [--tab profiles|graphics|controls|audio|plus|install]

The following files are stored next to fm3.exe:

fm3.exe can be launched without command-line arguments and reads these files automatically. While the game is running, F4 opens the SDK cvar editor and F3 opens the debugging overlay.

• Code generation: 15 functions reachable only through tail calls or vtables, plus three getters with a shared epilogue, required explicit function boundaries. config/fptr_functions.toml declares roughly 200 functions reached only through pointers such as vtables, callbacks, and thread entries. tools/find_fptrs.py finds pointers in .rdata/.data and lis+addi pairs; tools/prune_fptrs.py removes false positives. If the runtime stops with Call to invalid or unregistered function at guest address X, address X is probably missing from this list.
• Fibres: XAPI fibres use the native SDK implementation configured under [rexcrt].
• setjmp/longjmp: addresses 0x82534B20 and 0x825345E0 must be declared. Without them, libjpeg error handling corrupts registers and causes a crash when entering a race.
• cache: device: FM3 writes to paths such as cache:\replay_stream during races without mounting the device itself. Fm3App mounts it at user\cache_partition.
• Disc 2 content: installed packages require their licence headers and are registered through the SDK's ContentManager::InstallContent implementation.
• Project Forza Plus 3: the mod includes 18 pre-extracted content packages. Its default.xex belongs to the original 2009 edition and is not used. The port rebuilds the protected-file signature table in memory instead.
• Render-to-texture: readback_resolve = "fast" is fixed and hidden from the launcher. Readback is required for roads and vehicle thumbnails, whereas full is synchronous and caps FM3 at 30 FPS.
• Frame pacing: the SDK's vsync cvar represents the console vblank timer, not display synchronization. FM3 uses that timer internally and runs too fast without it, so it is fixed in fm3.toml. Achievement notifications are also disabled because an active notification causes the presenter to repaint at the monitor refresh rate, resulting in misleadingly high frame counters and severe pacing issues. Synchronous pipeline compilation and gpu_allow_invalid_fetch_constants follow the FM2 recompilation settings.
• Audio: FM3 submits blocks of only 256 samples, or 5.33 ms at 48 kHz. audio_maxqframes = 16 gives the audio queue enough headroom to survive brief CPU or GPU stalls without audible SDL underruns, for a maximum buffer of approximately 85 ms.

The patches under patches/sdk/ are applied by scripts\build_sdk.cmd:

1. 0001-user-profile-setters — active-profile name and XUID setters.
2. 0002-content-diagnostics — content enumeration and access diagnostics.
3. 0003-gpu-fixes-from-xenia — GPU fixes from newer xenia-canary/xenia-edge revisions, primarily addressing FM3's square shadows and road rendering:
   • d119505: rescale texture reads that use integer num_format.
   • xenia-edge c0e1129d7: force the sampler border-colour alpha to 1.
   • xenia-edge 4e2964f85: use point sampling for formats that do not support linear filtering under D3D12.
   • xenia-edge 9781a75a2: do not treat a texture with invalidated memory as already loaded.
   • xenia-edge c02060f22: downscale resolve readback when the internal resolution is above 1×. The included HLSL and GLSL shaders are rebuilt with Windows SDK fxc and glslangValidator; the latter can be built with scripts\build_glslang.cmd.
   • xenia-edge 2d7ca4fb3: do not report empty resolves as errors, eliminating approximately 170 unnecessary log messages per second in FM3.

The SDK is built with REXGLUE_USE_VULKAN=ON, but the port selects Direct3D 12 because the Vulkan backend does not yet render FM3 correctly.

Initial compatibility settings were informed by xenia-manager/optimized-settings and xenia-canary compatibility report #409. Xenia recommends readback_resolve = "full" for accuracy; this port uses fast because it preserves the readbacks FM3 needs without reducing output to 30 FPS.

The only FM3 entry in game-patches, Disable hash checks, does not match this Ultimate Collection default.xex and is not applied.

The release candidate was scanned with Microsoft Defender on 15 October 2026 (security intelligence version 1.461.35.0). No threats were detected in the packaged executables, libraries, or ZIP. This is the result of that specific scan, rather than a guarantee that every antivirus product will report the same result. No antivirus false positive was reproduced during this review.

The Forza 2 v0.3.0 release notes document generic or heuristic detections involving rexruntime.dll in that port's earlier 0.2.0 package. Those reports concern different binaries and do not establish the detection status of this Forza 3 release.

Built with the ReXGlue SDK and the work of the Xenia and XenonRecomp projects.

This is an independent preservation and compatibility project. It is not affiliated with, endorsed by, or sponsored by Microsoft or Turn 10 Studios.

FM2, FM3 and FM4 use automatic persistent shader caching and preparation of previously recorded pipelines. Synchronous compilation remains the stable default (async_shader_compilation = false), and frame-time diagnostics are disabled in normal play. The launcher clears old experimental overrides when saving settings. There is no experimental shader toggle in the normal UI. First encounters with uncached content may still cause compilation pauses.

The Support / Apoyar tab shares its layout and existing Ko-fi destination with the other Forza ports. Shader preparation remains automatic, with no manual preparation button.