if I comment line 66, I get the white wireframe on top of the green mesh.So, looks line the red linemesh is rendered over the white line.
To me, it looks like z fighting.
This is quite confirmed if I comment the code to create cylinderWireWhite and enable the line mesh.
Check Material | Babylon.js Documentation to see if this can be fixed.
Firstly, I want to display the mesh wireframe. And then users can choose edges they want, which will be highlighted. And users can also mark the edge as seam edge which has been choosed to a third color. Then I will unwrap the mesh through the seams.