Hey there! I don’t think the Simple Curves calculation is going to work exactly all the time, because the Hermite spline is cubic, not quadratic. I tried creating a simple interface to explore the effect of the tangent length on the curve between two points on a circle, and it can’t fit exactly:
Tangent to circle | Babylon.js Playground (babylonjs.com)
I think in your case, it might be better to calculate the points along the circles using trigonometric functions, and join them with the other sections.