Rhino 8 macOS ExtendSrf bug

Extending a natural surface with ExtendSrf, Merge off, and the Smooth option results in a trimmed surface. See the CP layout of the extended surface. In my opinion, this is a bug.


Surface extend bug.3dm (2.0 MB)

Every now and then, it makes the bottom edge a trimmed edge, so the bug isn’t even consistent; the right edge is always a trimmed edge. With this bug, resulting in two trimmed edges, I can’t even use the also defective RefitTrim tool to obtain a natural surface.

Bump.

The original surface itself is a trimmed surface:

How’s that even possibly possible? I used EdgeSrf to build it and left it as it is.

@Lagom
I don’t know. I am not aware of EdgeSrf creating trimmed surfaces. If you can reproduce the creation of this with EdgeSrf, pls send a file.

Edit: I did a quick code investigation, and it doesn’t seem possible from the code, that the command produces trimmed surfaces. Were other commands involved before you noticed the issue with ExtendSrf?

Uh, yeah, many tools were used, but I can’t remember in which order. I try to re-create the file above again.