Help with Blendsrf

Hi, So Im practicing rhino through youtube, trying to model a parametric leaf shaped roof. As you can see in the section, its not the same thickness all through out. I followed everything on the video, create surface, offset surface, then turn on record history before blendsrf, then adjusting the control points for the thickness. However, when I try to move my control points even the slightest, it totally messes up my blended surface as shown. what could be the problem, and how to fix it? thanks

Without the 3D file, hard to say anything useful.

Have you already tried to select the twosides from the same correspondant point?

This happens to me when I select partial edges crossing the selection points.

14 Rhino Beginner course for Architects_Massing part 13_Double Curvature Forms 6.3dm (9.0 MB)

this is the youtube video im practicing on.
14 Rhino Beginner course for Architects_Massing part 13_Double Curvature Forms 6

yes, I have, to no avail

Most peculiar. Works fine here, Rhino 8, macOS.
BlendSrf history.3dm (66.4 KB)

Hi @deo14
I’m seeing the same weird behaviour, but only with your original BlendSrf. If I recreate the BlendSrf, it acts as expected - weird indeed! What SR are you running?
-Jakob

For me, the problem only appears while the surface is present in the middle. As soon as I remove it, the issue disappears, and if I move the control points, the problem also disappears.

It appears that you are running Rhino 8.2 and I fail to find any licensing information.
The current version is 8.31…
I’d start there.
-wim