Use Trail Renderer to form a weld fillet(welding joint) between two objects

Hi,

I am making a project which requires to show welding(https://en.wikipedia.org/wiki/Welding). I need to form a weld fillet (weld joint) between two objects through script. I suppose tail renderer can do the job, but cannot modify it to create a joint based on time and the spill of the fillet. Can someone help in this direction or suggest a way to do it ?