Hello there
I’m trying to do a simple sweep 1 on a closed curve, but rhino creates wierd geometry following the control points instead of just nicely following the curve (see below)
I cannot simply “rebuild” the curve as it must match the borders of another surface (and if i simply rebuild there will be some discrepancies)
Any clue?
thanks!
Hello - see if ‘refit rails’ on the Sweep control fixes that. If not, please post the inputs in a 3dm file.
-Pascal
tablebassebois final.3dm (4.4 MB)
thanks for your answer!
no it didn’t fix it
please find the file attached
Hello - thanks - I cannot tell what you’re using or asking about in the file - please post a file with only the inputs for the sweep.
-Pascal
tablebassebois final.3dm (3.6 MB)
Sorry about that!
So i put the construction lines on the layer RED (and they are displayed in red)
and the part where I have a problem is on the Yellow layer (displayed in yellow)
You’ll see how in the right angle the sweep doesn’t follow the rail neatly.
In case you wonder, the rail was created by duplicating the border of another sweep.
Cedric
Hi Cedric - it looks like a problem, if not the problem is in this part of the rail:
The segments are all a little or a lot (~4 degrees) out of tangency.
If you replace that with a Fillet at 7.1 degrees, the sweep is clean there.
-Pascal
Thanks a lot Pascal for taking the time.
Clearly this is the cause of the problem.
However, I’m still kind of blocked.
If I do as you suggest, and replace the faulty curves with one 7.1 fillet, i can do a sweep, but the resulting surface won’t “touch” the adjacent surface anymore (the one that was used to generate the faulty rail by “duplicate border”). I don’t know if this is clear. Any idea how I can solve this? (see below)
Next obvious question coming to mind is why am I having these tangency issues in the first place. I started all this with a curved line, did an ExtrudeCrv, used the border of the newly created solid to do a first sweep, and then used the border of this new surface to try and do the second sweep (see below). Maybe there is an obvious reason to this that I’m missing?
thanks!
Hi Cedric - it is a little hard to tell where you started but it looks to me like possibly the inside of the ‘v’ shape:
If so, this surface is a bit messy:
With messy curvature:
If that surface is meant to be a clean arc, then I would build it that way to begin with say with FilletSrf at 3
Then things like offsetting to get the thickness will be a lot cleaner and the new offset edges will be tangent arcs as well.
-Pascal
super clear thank you so much
