Same Curve, Different CtrlPts for Rhino 6 & 7?

Can anyone explain this? If I use the same steps to create this curve in Rhino 6 and Rhino 7, I get different Control Points. Even if I draw this curve in Rhino 6 and Copy/Paste it into Rhino 7 (Or from 7 to 6), I see different CtrlPts. Why is this?

Polygon: 4 sides.
Fillet Corners.
3dm file attached.
Polygon Fillet CtrlPts.3dm (2.0 MB)

Hi MIke - in V7, Sub-curves retain their ‘identity’ and structure. Previously a polycurve took on the highest degree, of the the sub curves that it contains, for the entire curve.


Hi Pascal,

So the straight sections are retaining their Degree1 structure instead of transforming to Degree 2 to match the fillets in Rhino 7? OK, I think I get it, and I can see advantages. It just caught me by surprise. I hadn’t really noticed this change before.

Thank you for the explanation.