Is it not that certain train lines are somewhat deep underground? The Piccadilly line swims with respect to the ground in the centre of town, when it is below ground. Further out where lines are at the surface the routes stick to the ground correctly.
I saw a project like that here in hn recently for all uk trains even. it'd be pretty cool to extend this to support that, busy stations might be visually confusing, thanks for suggestions
Quick suggestion: When not tracking a train, the mouse wheel should zoom into / out from where the cursor is pointing, rather than the center of the window.
The train paths are drawn on a 2D layer above the buildings, not at z-index that matches the proper 3-D position. So the paths appear to weave around and over the tops of buildings.
Edit: Is there a Repo to look at and learn from this?
Quick suggestion: When not tracking a train, the mouse wheel should zoom into / out from where the cursor is pointing, rather than the center of the window.
There is a good wiki page on this: https://wiki.openstreetmap.org/wiki/Simple_3D_Buildings