Welding Pool Demonstration in WPF

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C#

WPF

I'm trying to develop a welding simulator in WPF C#. I have already designed an electrode and two welding materials in WPF environment. Right now I need to demonstrate the welding pool (when electrode comes near the welding materials). I simply used a PolyLine to draw a line as weld pool, but I need it to be more real, something like the following picture:

http://www.practicalmachinist.com/vb/attachments/f30/1351d1201814271-contaminated-weld-pool-filler.jpg

So now my problem is to demonstrate this weld pool after it gets cold. Can I change the polyline outline to some sort of continuous arcs? or is there any other tools in WPF useful for this purpose?

I'm not a pro in these stuff, but I tried to explain it clear; sorry if I don't make any sense!