I have a slightly uneven poly circle. Is there a way to automatically (not manually) find the best-fit circle, i.e. one that minimizes the sum of distances from the poly? It's like finding a "best fit plane" for near-planar points, but for a circle. There's a "Fit Curve" SOP, but it seems to create a very close NURBS approximation of the shape, not a perfect circle.

Is this circle 2-dimensional or 3-dimensional?

johnmather
Is this circle 2-dimensional or 3-dimensional?

2-D on the XZ plane

In that case, you can approximate the result algebraically by performing something like this: https://scipy-cookbook.readthedocs.io/items/Least_Squares_Circle.html#Using-an-algebraic-approximation [scipy-cookbook.readthedocs.io]

I've attached a hip file that should do what you want. If you scrub the timeline, you'll be able to see the results for different inputs.

johnmather
In that case, you can approximate the result algebraically

Excellent, works great. Fortunately, my poly is static, it doesn't rotate or change shape