Surface fillet result not understood

I’m trying to fillet some surfaces but the result is another surface object that rather than a modeling of the surface edges. What am I doing wrong here?

FilletSrf (surface fillet) will only look at two surfaces at a time. In a situation like this, where more surfaces are joined together, you might want to try FilletEdge.

I tried the fillet edge and there was some improvement but still issues. I attached the model. Perhaps I’ve made some construction faults? (568.4 KB)

This is frustrating. I can’t manage to make this object behave. Whether its non joined surfaces or a single polysurface solid, I can’t get the filleting to work properly. (732.8 KB)

This FAQ should be instructive:

It was written for Rhino V4, so some of the techniques are no longer needed for V5, but the overall limitations and techniques are very useful for fully understanding how to use Rhino’s two surface filleting tools, and what to do when your situation can’t be handled directly.

The edges are not all joined - the bits that are skipped are naked edges- FilletEdge will not (should not) show you these as selected edges. So you need to clean that up, if you want to filletEdge, but filletSrf seems like the better bet here.

Then, there’s this, in the middle:

The white is a section curve through the surfaces- see what I mean? That’s going to make a mess of any filleting in this area…

@JKayten, in case it helps, I’d go after this as in the attached file:

CocoColaPony_1_PG.3dm (909.5 KB)

@JKayten, one other thing - it looks to me like the cut-in surfaces, the blue one in my image, were made using NetworkSrf - just fyi, I’ve found that that command prefers to have a ‘reminder’ curve from time to time as, in this case, a cross section across the short direction. In other words, avoid trying to fill long, skinny rectangles that have no section curves to break them up into sections more approaching square, or at least be prepared to go back and add a curve or two if this sort of thing happens. You don’t want to over define with curves either, but I’d try to avoid really long rectangles what have a high (far from 1) aspect ratio.

@JKayten More monkeying - SoftSofterSoftest.3dm (499.4 KB)


Thanks Guys, I really appreciate the help!

I didn’t see this till this afternoon. Thanks! So what I see is I can create a cutaway and use it to shape the positive volumes. You’re right about my use of the network curves tool. Is using loft a better choice in this instance? Also, I continue to have issues with filleting. These two shots show the two attempts and the error messages. I’m not sure what “failure in building corners” and “Failed to split surface” indicate.