Hi Brian

I have returned to original truchet pattern, but with a different approach.
To do this I have created a macro: ArcCenter. Hopefully this will be replaced
with an Arc node with centre, 3 points and tangent options in the near future.

Given that it is covering old ground, I have posted it here rather than
"playing with nodes" thread because I thought it may be a interest to you alone.

Have a great weekend
James