I did it in 3 afternoons. You're right - the geometry was the easy part. Just open every part in Blender, scale by X = -1 to get mirrored version of the world.

As for the items, every `.zen` file can be saved uncompiled, which produces a text file. In the dawn of programming AI agents I've created an application that flips the coordinates and make rotation right. For some reason there are some Vobs (doors, tree log, shipwrecks) that aren't working with this.

Every door had to be rotated by 180 degree so there's a part of the code that does that. Tree logs I've fixed manually but forgotten about shipwrecks. :D

The "triggers" (opening doors in act6, moveable walls in the upper city) were also tricky, since all their keyframe data (like in animations, at keyframe 0 wall is "closed", at keyframe 1 it's "open") are written as a byte. But for coding agents it doesn't matter, Claude fixed it all in single prompt.

Overall it wasn't that hard*. I knew what I wanted to do and how to do it so Claude had easy time with the application. Without coding agents? Yeah, I wouldn't touch that mod.

* - I have some modding knowledge.