duplicate a mesh

I want to build a mesh which will be duplicate in my game if I touch him.
How should I do ?
Thank you for your help !

It depends on how you define duplicate. Do you just want a new mesh to be placed or an entirely new blueprint?

This is a solution in case you just want the blueprint to spawn a new mesh, when an object collides with the collision of the blueprint.
Of course you might want to do the math a bit more complex, to not just create a long line.