u/EnzoDeg40

If you’ve ever installed mods or just looked through the game files, you’ve probably noticed that the game data is stored inside .ovl packages, a proprietary format.

Having played RCT3 during my childhood, I always wanted to understand how I could modify or extract the game’s data. This weekend I seriously started digging into it after buying the game on Steam (I already had it on CD and on Epic Games lol). Also, I never really played RCT1 or RCT2 that much.

Some GitHub projects (hi open-rct3 and ovl-extractor2) already managed to extract a few things like package names, dependencies between packages, and sometimes textures, but that was usually where the information stopped. What I really want is to extract the 3D models and import them into a game engine like Unreal Engine or Blender to make renders while keeping that retro aesthetic.

Yesterday I finally managed to extract the polygons. Now I still need to figure out how to determine their scale and how to correctly apply the textures. Animated 3D models are not extracted yet.

A large part of the work involved in understanding how the packages are compiled was helped by Claude Code and Codex. That doesn’t mean the whole project was vibe-coded, but it really shows how modern LLMs can help research very specific technical tasks, especially since I didn’t originally have deep knowledge in byte-level file parsing, variable conversions, and similar low-level topics. I’m definitely starting to get into the technical details now.

My progress and findings are available on GitHub. It’s pretty technical at the moment, but I’ll probably make another Reddit post later to share future progress:
https://github.com/EnzoDeg40/OVLExtractor-3/tree/dev
(I really didn’t go very far with the project name lol)

Also, if you’d like to share what you would do if we could fully extract the game data, I’d love to hear your ideas.

https://preview.redd.it/gt4f7x4i4g3h1.png?width=2484&format=png&auto=webp&s=a6669cbd3e0ba52c3344e4fce4a8492547cd9bd3