The map is a simple grid of tiles, which vertices are rotated around the "map"’s border using a vertex shader.

Rotation of walls and trees is done CPU-side so that the models’ shapes don’t change. Being pretty illiterate at real-time rendering programming at the time (today, I know enough to not get stuck too long in my projects), I didn’t realise I could have got the same result using the vertex shader by providing the model’s pivot point.

It was while working on this project that I began porting my small game engine, which was only OpenGL3-compatible at the time, to DirectX12.

More info here (in French): https://www.developpez.net/forums/d1539963/applications/developpement-2d-3d-jeux/projets/wejv5-map-tapis-roulant/