
Blitz3d Decomp
Decompile a Blitz3D game to readable Blitz source with B3DDecomp and port what it does...
Install
npx skills add rehan-remade/universal-modder --skill blitz3d-decomp -g -a claude-code -y- Repository
- rehan-remade/universal-modder9.3k
- Category
- Engineering
- Updated
- 3d ago
- License
- MIT
- Context cost
- Lightabout 1,190 tokens
- Runs scripts
- Yes, review before use
What it does
Decompile a Blitz3D game to readable Blitz source with B3DDecomp and port what it does to another engine. Covers SCP - Containment Breach-era and other .bb games, B3DDecomp, Blitz3D runtime behaviour (fixed tick, Animate, CurveValue, Euler angles, quaternions, Rnd), animated .b3d models (viewmodels with bones and keyframes) into Roblox, and where to stop (builds protected against decompiling, games and assets the user has no rights to). Use when a Blitz3D game's code or animated models are needed.
Blitz3D decompile and port
Blitz3D games ship as one exe: the runtime in .text and the compiled game in a resource module that
the runtime links at load. Ghidra on the exe shows only the runtime. The route that works:
B3DDecomp disassembles the module and decompiles it to Blitz source. Then the source is the spec for the
port, and the original game stays the oracle.
Keep every disassembly and decompile outside any repo (convention: ~/<game>-decomp/), and never
publish them; the scripts here are fine to keep. Leave proprietary DLLs that forbid decompiling alone: their
export names in the exe are enough. Journal in the mod's MODLOG.md.
Read the source when there is one: SCP: Containment Breach (Regalis11/scpcb) and its Ultimate Edition Reborn fork (Jabka666/scpcb-ue-my) are open source under CC BY-SA 3.0.
What a port may use. A port that re-expresses a game's logic, or converts its models, keyframes, textures or sounds, redistributes that game once it is published or uploaded (to Roblox too). Port only what the user has the rights to: their own game, or an openly licensed one on its terms (SCP: Containment Breach: credit it and keep the port under CC BY-SA 3.0, and check each asset's credits, since fan games mix licences). Anything else stays a private study: nothing from it is uploaded or published.
1. Tools
- B3DDecomp (juanjp600/B3DDecomp, C#, GPL-3): clone outside the repo, then
dotnet build Blitz3DDecomp.sln -c Release. It needs a .NET 8 SDK; a user-local one installs without admin (dotnet-install.ps1 -Channel 8.0 -InstallDir <dir>). Run withDOTNET_ROLL_FORWARD=Majorandbin/Release/net8.0onPATH: the decompiler startsBlitz3DDisasmby name. - If one function aborts the whole run, apply
references/b3ddecomp-skip-failures.patch (
git apply; made on commit 2b3148b): the decompiler then skips a function it can't finish, with astep5 failedline, instead of stopping.
