OpenIGI: WebGPU independent reimplementation of Project IGI

OpenIGI, a clean-room reimplementation of Innerloop Studios' engine for Project I.G.I.: I'm Going In (2000) and I.G.I. 2: Covert Strike (2003), runs both games from a user's own retail installation using a single renderer on Direct3D 12, Vulkan and WebGPU, including in the browser. The engine is written in C# on .NET 10 and reproduces the original's deterministic 30 Hz simulation, AI perception, weapon tables and mission flow, with a vanilla mode held pixel for pixel as a regression gate. All 14 Project I.G.I. missions are playable, the first 6 in the browser with original graphics, while all 19 I.G.I. 2 missions load and play but have no released builds yet and must be run from source.

An open-source engine for Project I.G.I.: I'm Going In 2000 and I.G.I. 2: Covert Strike 2003 . OpenIGI is a clean-room reimplementation of Innerloop Studios' engine, written in C on .NET 10. It runs the original games from your own retail installation. The original missions, scripts and AI play as they did in 2000, and a modern renderer, launcher and modding platform are built around them. openigi.com https://openigi.com · Releases https://github.com/OpenIGI/OpenIGI/releases · Modding guide https://github.com/OpenIGI/OpenIGI/blob/master/sdk/README.md · Contributing https://github.com/OpenIGI/OpenIGI/blob/master/CONTRIBUTING.md You need your own copy of the game. OpenIGI contains no game assets and none of the original code. Every texture, model, sound and script comes from the installation you point it at. - Faithful to the original. The game's own QVM scripts run on a reimplemented interpreter, over a deterministic 30 Hz simulation that reproduces the original's timing, AI perception, weapon tables and mission flow. A vanilla mode reproduces the original picture and is held pixel for pixel as a regression gate. - A modern renderer. Deferred HDR rendering with cascaded shadows, real-time global illumination, volumetric fog, screen-space reflections, temporal upscaling and hardware ray tracing on capable GPUs. NVIDIA DLSS Super Resolution, DLAA, Ray Reconstruction and Frame Generation and Reflex are offered as an optional download. - Direct3D 12, Vulkan and WebGPU. One renderer runs on all three. It runs natively on Windows, Linux and macOS, and in the browser. - A launcher. It finds your games, installs and updates OpenIGI on the stable or beta channel, and manages content packs and mods. - Moddable. You can replace art by dropping files in a folder, install content packs with a load order, or write code mods in C against a versioned API, published through a community index and built from source. | | Project I.G.I. | I.G.I. 2 | |---|---|---| | Campaign | All 14 missions | All 19 missions load and play; in development | | Released builds | Yes | Not yet, run from source | | Browser | First 6 missions, original graphics | No | | Multiplayer | No | No | | Platform | Graphics API | Hardware ray tracing | |---|---|---| | Windows 10/11 x64 | Direct3D 12 default , Vulkan | Yes, on DXR 1.1 / RTX- and RDNA2-class GPUs | | Linux x64 | Vulkan | Yes, on RTX- and RDNA2-class GPUs | | macOS 13+ Apple silicon | Vulkan through MoltenVK, included | No: shadows, reflections and GI use their screen-space and shadow-map forms | | Browser | WebGPU | No | Desktop. Install the launcher from openigi.com https://openigi.com . On Windows that's a download. On macOS and Linux run: curl -fsSL https://openigi.com/install.sh | bash The launcher looks for your game installations, or you can point it at them in Settings. It installs OpenIGI and keeps it up to date. Switch to the beta channel in Settings for builds from the development branch. Browser. Open openigi.com https://openigi.com in a browser with WebGPU and choose your Project I.G.I. folder. The files are read on your machine and never uploaded. You need the .NET 10 SDK the version is pinned in global.json https://github.com/OpenIGI/OpenIGI/blob/master/global.json . dotnet build -c Release OpenIGI.slnx dotnet test -c Release OpenIGI.slnx Tests that need retail data read IGI GAME PATH and IGI2 GAME PATH , and skip themselves when those are unset. A checkout with no game data still builds and tests clean. Some optional native components are fetched into third-party/ rather than committed: | Script | Needed for | |---|---| | tools/fetch-wgpu-native.ps1 | The desktop WebGPU backend | | tools/fetch-streamline.ps1 | DLSS and Reflex in development builds | | tools/fetch-dxc.ps1 | Regenerating the committed DXIL shaders | Copy the build into the game folder and run it there, or tell it where the game is: export IGI GAME PATH="/path/to/Project IGI" PowerShell: $env:IGI GAME PATH = "C:\Games\Project IGI" export IGI2 GAME PATH="/path/to/IGI 2" dotnet run -c Release --project apps/OpenIGI.Desktop -- -title igi1 | Option | Effect | |---|---| | -title igi1\|igi2 | Which game to run | | -game <dir | The installation to read, ahead of the environment variables | | -mission <n | Start in a mission, skipping the menus | | -window , -size WxH , -fullscreen | Window mode. Borderless is the default | | -difficulty easy\|normal\|hard | Difficulty | | -vanilla | The original menus, picture, pacing and audio | | -content <dir | Load a content pack folder | | +<command | Run a console command at startup, for example +gfx preset ultra | -help lists every option, including the capture and camera tools used in development. The graphics presets are vanilla , enhanced , high and ultra . Each one sets the renderer's variables together; every setting can also be changed on its own in the settings pages or the console . The graphics API is chosen automatically: Direct3D 12 on Windows when the GPU supports shader model 6.6 , Vulkan elsewhere. Override it with r renderer , or press F10 to switch APIs while the game runs. DLSS and Reflex need an NVIDIA RTX GPU on Windows. Install them from the launcher's Content page NVIDIA DLSS . Without them the engine's own temporal upscaler runs. Settings are saved to settings.cfg beside the executable if one exists there, otherwise to your user profile: %APPDATA%\OpenIGI , ~/.config/OpenIGI or ~/Library/Application Support/OpenIGI . - Replace a file. Put it under <game /overrides/ at the path it has in the game, for example overrides/common/textures/000 04 1.tex . A .res archive there works too. The overrides console command reloads the folder, and F8 toggles it. - Content packs. These are folders of replacement art with a load order, installed and ordered from the launcher's Content page. The tools to build one from your own installation, such as an AI-upscaled texture pack, are tools/texture-forge and tools/OpenIGI.Tools.ResExtract . - Mods. A mod can ship files that stand in for the game's, whole new missions and campaigns, C code, and shader passes over the picture, before the tone map or after it. Its code is one Configure that says, top to bottom, what it changes through a builder: settings, level systems, task types, script constants, the games' events and HUD overlays. A save records the mods it was made with, and a mod's tests are built with the same SDK against a harness that configures it as the game does. Start one with the template --kind code , data or shader : dotnet new install OpenIGI.Modding.Templates dotnet new openigi-mod -n MyMod --modId my-mod Mods are published through a community index and built by its CI from a pinned commit of their public source, never from an author's binaries. The launcher's Mods page installs them. See the modding guide https://github.com/OpenIGI/OpenIGI/blob/master/sdk/README.md . apps/ OpenIGI.Desktop the game , OpenIGI.Launcher, OpenIGI.Web the browser build src/ Core/ primitives, settings, retail file formats, the QVM interpreter, release manifests Engine/ the game host and frame loop, virtual file system, mod API and loader Game/ gameplay shared by both games, each game's own gameplay and presentation, the menus Rendering/ the renderer, its hardware interface, the D3D12/Vulkan/WebGPU backends, shaders, DLSS Audio/ OpenAL and Web Audio Platform/ windowing and input for desktop and browser UI/ the UI framework used by the menus and the launcher sdk/ the modding SDK, the project template and the community index's rules tools/ asset extraction, QVM disassembly, shader build, release and site tooling tests/ xUnit test projects Nothing under src/ may reference a concrete backend; the applications wire backends in. The architecture tests in tests/OpenIGI.Core.Tests/Architecture enforce this layering. Contributions are welcome. CONTRIBUTING.md https://github.com/OpenIGI/OpenIGI/blob/master/CONTRIBUTING.md covers the determinism rules, the clean-room policy, which retail build is the reference, and how changes are tested. In short: open a pull request against develop , keep the Release build free of warnings, and keep the test suite passing. tools/install-hooks.sh installs the same checks as git hooks. OpenIGI is licensed under the GNU General Public License v3.0 https://github.com/OpenIGI/OpenIGI/blob/master/LICENSE . Third-party components are listed in THIRD-PARTY-NOTICES.md https://github.com/OpenIGI/OpenIGI/blob/master/THIRD-PARTY-NOTICES.md . OpenIGI is a clean-room reimplementation for use with game data you already own. It is not affiliated with or endorsed by the owners of Project I.G.I. or I.G.I. 2 . All trademarks belong to their respective owners. The repository contains no game assets, original source code or decompiler output, and contributions that include them are not accepted.