How to make support made tunnels.

These can be dark inside and light on the outside. You have to follow these steps.

You have to have a invisible track and use simple track connectors. Place them end to end on the hidden track spline like this.

Then you need to use custom support like this.

Make sure you extend the ends a bit on each end.

You will end up with this.

Then make the whole support spline dim like it is in a tunnel and color it pitch black.

Then import that same dimmed support spline and make its heartline like -7 or 8 feet. That will raise up the roof.

Then you have to import it again and change the support properties to this.

Still be sure to extends the ends a bit.

Then you will have the finished inner tunnel layer.

could you tell me why anyone would want to use that method? it seems terribly inefficient and very resource- and time- expensive

It required no scripting or use of blender or sketchup at all. I have been using this method for many years in Jamp Up Land and most of my parks.

What is the clearance on the inside when doing this method?

You can make it fit the clearance of the steel looping tunnel.

Why not just use the concrete tunnel provided by the game itself?

I can use my method to make a inner layer of custom supports. Like this.

But then the outside of the tunnel will not be wood.