Is it possible to extend a surface with a new surface of fixed radius?

I am looking for a way to extend a surface as if I am filleting up to the edge I am extending. A bit like you can do with polyline Mode=Arc. What’s the best approach for this?
Basically what I need to make is a transition between two surfaces that consist of a fillet with radius 10 and a fillet with radius 5 as in the attached (simplified) example.(Even better would be a blend surface where you could input 2 radii, similar to arcblend. Regarding arcblend: would be nice if I could make 1 of the radii a chosen size)
extend_with_fillet_Rv5.3dm (113.3 KB)

Hi Gijs - I guess you can only do this at the curve level. If you make an arc extension of an edge, say, you can sweep that along the edge you want to extend with the Align with surface option in Sweep1.


yes, in this simple case that can be done, but for a more curved surface (with probably trimmed or non-square UVs) this method won’t work. And I wonder if sweeping along rail you will always get a perfect rolling ball fillet

Hi Gijs - it should work - I guess it is not an extension always, at the ends though - OrientCrvToEdge may be a step though.
extend_with_fillet_maybe.3dm (226.6 KB)


thanks, that seems to work. I have also found another way: offset the surface and pipe the resulting edge then trim…