How to make 3D tracks

I've been making (fake) 3D tracks in Mario Kart PC for two years now, and I'm starting to see more people making them, so I'm going to share some tips for those who want to try it. You can compare them to this track https://mkpc.malahieude.net/map.php?i=236284. Feel free to add any other tips.

To get this effect, you need to use 2D objects, which you can place next to each other to create walls, for example. The wall will have the thickness of the 2D object you're using.

To make 3D elements created this way look good, you need to smooth out the angles by rounding them off, to avoid giving the edges of the 3D wall a stair-step effect.

For lighting your cylindrical 2D objects, I find that the best approach is to make the center and top lighter, while making the sides darker.
You can make ceilings by leaving empty space underneath your 2D object, but this is a bad idea because it's time-consuming to do and it also adds lag (here's an example: https://mkpc.malahieude.net/map.php?i=148868).

You was commented on my 3D track,you want to me rounding hem off and a have a question,i must crate new decorations?

You can use your decorations and erase the corners a bit to make them look rounde

But how

copy and paste your decoration into Paint, then placing it into the MKPC decoration editor