How do you convert a linear data (shapefile) into a tunnel in CityEngine?

Question

Can someone help me with the cga code to convert a line into a tunnel in CityEngine?

AKINOLAEKUNDAYO · Answer

Thanks Ivan,

Where have you been?

LR · Answer

Here's a basic approach for a hollow cylinder - I insert a disc, move/extrude it and then delete the center. Again, straight lines only. version "2016.0" attr shapeType ="" attr TunnelLength = 0 @StartRule Lot --> case shapeType == "Street": MakeTunnel else:NIL MakeTunnel --> set(TunnelLength, scope.sx) alignScopeToGeometry(zUp, any, world.lowest) primitiveDisk(20, 5) center(xyz) r(0,90,0) t(-scope.sx/2,0,-TunnelLength/2) extrude(TunnelLength) setback(1){all: TunnelColor | remainder: NIL} TunnelColor --> color(1,1,0)‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍

AKINOLAEKUNDAYO · Answer

LR, much appreciated. Apologies! Did not make myself clear enough. I was looking for a railway tunnel - cylindrical in nature.