Adds gc-engine's binary and a level.rs that joins the format layer to the renderer: LOD selection and morphing per patch, then triangles grouped by texture so each texture is one draw rather than one per triangle. The PS2 world is Z-up at 1024 raw units per world unit, so the conversion is (x, y, z) -> (x, z, -y). The sign flip on the third axis turns the PS2's right-handed frame into Bevy's left-handed one rather than negating a determinant, which is what stops the level rendering mirrored. Morphing and collapse are kept distinct. Morphing blends a vertex toward the midpoint of its two parents across its tier's band; collapse replaces the vertex outright, position and UV, once it is past the far edge. Morphing is a blend, collapse is a cut, and conflating them makes distant terrain shimmer. Blending has to happen in raw units before the axis swap: mixing a converted parent with an unconverted child scales the blend by 1024. Level 0 renders as 26,758 textured triangles over 92 textures, correct UVs, with LOD selection live (26 patches at LOD 0, 650 at LOD 2 from the start camera). GC_ENGINE_SHOT writes one frame as a PPM and exits. Rendering immediately exposed a bug no test could. Positions are i16 offsets from a per-patch origin, and the obvious rule -- the last non-index STROW row -- is wrong on RAC2, which also uses STROW for per-vertex light records that come *after* the origin. Taking the last one yields [186, 186, 186, 186] and collapses the whole level onto the world origin. The entire level then fit in a 63-unit box and every test still passed: vert_count matched, tri_count matched, every parent and triangle index resolved, because all of those are relative to the same broken origin. Only a screenshot showed it. The rule that works is the STROW immediately preceding the first V3_16 position unpack; with it, level 0 spans x 86..444, y 46..211, z -477..40, matching the patch bounding spheres. That is worth more than the renderer: a parser can be completely self-consistent and still describe the wrong thing, and where a value is absolute rather than relative it has to be checked against something independent. The frame is flat and dark because there are no normals and no lighting yet. That is the next task -- the per-vertex light records -- not something to paper over with an exposure fudge.
Going Commando
A native PC reimplementation of Ratchet & Clank: Going Commando (PlayStation 2, 2003), written in Rust.
The game is reimplemented, not emulated. There is no MIPS interpreter here and no CPU emulator: the systems are ported to Rust so they run as ordinary native code.
Status: initial scaffold. The disc is identified and verified, the
workspace builds, and nothing else is implemented yet. See
docs/roadmap.md for where things stand and what comes next.
The target
| Game | Ratchet & Clank: Going Commando |
| Platform | PlayStation 2 |
| Disc | SCUS_972.68 v1.01, USA Black Label |
| Video | NTSC, 60 Hz |
| Boot ELF SHA-1 | bacda860cbd6723142e86db56f197e47e728970f |
Verified against a real disc — see docs/disc-identification.md.
This is the build the reference projects pin; Greatest Hits v2.00 is a
different binary and is not the target.
No game content
This repository contains no game assets, no disc images, no BIOS dumps and no proprietary toolchains. You supply your own legally obtained copy of the disc as an input, the way the upstream reference projects do.
A pre-commit hook enforces this, blocking disc images, asset directories, container signatures and files over 50 MiB. If you clone elsewhere, enable it:
git config core.hooksPath .githooks
Layout
crates/
gc-formats/ asset format parsers (pure, no I/O beyond the caller's buffer)
gc-extract/ disc pipeline: identify, unpack, verify
gc-game/ game logic: hero, weapons, moby classes, progression, saves
gc-video/ IPU / MPEG-2 decode
gc-engine/ Bevy app: Graphics Synthesizer, VU0/VU1, renderer, frame loop
docs/
disc-identification.md which disc we build against, verified
roadmap.md phases, gates, current status
plan/ one file per subsystem, written as work proceeds
formats/ format specs, written as formats are reversed
tools/
identify-disc.py identify any Going Commando disc image
vendor/
rerac/ pinned upstream reference checkout (not tracked)
Building
Requires a Rust toolchain via rustup.
cargo check --workspace
cargo test --workspace
The host audio backend is disabled in Cargo.toml (see the comment there) so
that the workspace builds without system ALSA development headers. Audio decode
is the last phase of the port and lives in gc-video; re-enable it and install
alsa-lib-devel when that work starts.
Identifying a disc
python3 tools/identify-disc.py <your-disc.iso>
Reports the serial, version and video mode from SYSTEM.CNF, hashes the boot
executable, and warns when the disc is not the supported build. Reads only a
few megabytes, so it is near-instant.
How it will be verified
Visual and behavioural comparison against PCSX2, replaying recorded input and
comparing frames, level by level. The PS2 float model is reproduced rather than
approximated — see AGENTS.md.
Credits and licensing
This project learns from and is built on the work of others. Licences are
recorded in PROVENANCE.md and notices must travel with any
code derived from them.
- ReRAC — a native Rust/Bevy port of Ratchet & Clank (2002), the first game. ISC. The architecture this project follows.
- OpenRAC / rac2-gc-decomp — matching decompilation research for this game. MIT. Source of verified struct layouts and engine documentation.
- Wrench — community documentation of Insomniac's container formats. GPL, used as a specification reference only; no code is copied.
Ratchet & Clank is a trademark of Sony Interactive Entertainment. This is an unofficial fan project, not affiliated with or endorsed by Sony Interactive Entertainment or Insomniac Games.