The Half-Tube Tutorial for Swift 3D V2.0

Make a Torus and a Cylinder. Size them up roughly as per the image on the left.

By using the torus as a guide we will build up the half torus with several cylinders.

Zoom in and size up the cylinder to match the torus segmentation. Make lots of copies and align each cylinder with each torus segment. I moved the torus back 1 pixel so you can see the cylinders as you put them in place.

( The higher the quality, the more segments you will have to make).

Make sure you select the Spin Rotation button so the cylinder swings only on the required axis.

Keep building by copy and pasting the cylinder as you build up the half torus, aligning each new one as you continue. Watch for cylinder length - it varies from segment to segment, so adjust as required.

Continue until you have made a 90 degree section.
Group all the cylinder sections together then copy and paste it.

Align the new cylinder object with the current one.

Delete the torus guide and you should have this result.

Your final image. If you want it more detailed you will have to make more segments.