Please explain to me in three.js how to add a solid border to the cube edge.
Or please send me a sample of your code.
Thank you in advance.
As you have provided no details about what kind of border you need
One option is to use
EdgesGeometry. Here is one oversimplified example with a prism (click on the image to run it):
Another option is to use a texture:
Correct! Thank you very much.
More common solution for boxes: How to render geometry edges? - #7 by prisoner849