# How to create a segmented Tube?

I’ve seen examples of creating infinite tubes using a list of points, converting them to a list of vertices, generating a `CatmullRomCurve3` and then using that for a `TubeGeometry`. But I want to create a “tunnel” that has 4 parts like so (excuse the horrendous sketch):

Through the gaps you can see outside the “tunnel”. The bottom of this tube is a flat plane, to mimic a road. I could give the cylinders a certain theta end like `Math.PI / 2` to make it 25% of a circle and position them a certain way, but I’m not sure how to have all of the 4 pieces follow the same curve to make it “feel” like a single tube.

1 Like

Thanks for the challenging question.

• Easy way: use a texture with transparent areas that correspond to the gaps
• Hard way: make a parametric geometry that builds a part of a circular tube

I tried the hard way and here is what I came up with. I hope it can provide you with enough hints or ideas.

https://codepen.io/boytchev/full/poxpGZN

3 Likes

I went another way, with a curve.

3 Likes

In @PavelBoytchev’s solution, the flat part on which you move always stays down. In @prisoner849’s solution, you rotate in the tube and the flat part is in different positions.

I have not yet found a solution for the rotation in my problem Inaccurate adjustment when cylinder is deformed. Must see if I can learn something from these solutions.

I updated the codepen, found a very interesting solution from @ycw to keep camera stable, so the flat part of the tunnel is always oriented horizontally. Comments are in the code.

1 Like

Wow some terrific solutions. I’m going to try and wrap my head around the codepens, thanks so much for the help!