I have a loft created from multiple lines. There are two lines that share a starting point and the loft between these two surfaces fail at creating a sensible surface. I’m not so interested in why the loft fails, but rather what is wrong with this surface. If I untrim it, I get a surface with the exact same length boundary, but the area is 1.5 times bigger.
what can be the reason for this
failed surface.gh (12.1 KB)
I notice that this surface has a decreasing domain in the u direction, but I don’t know if that would cause the problem with the area calculation.
Hej Timo -
FWIW, I can’t reproduce that issue when I use the edges of your surface:
To find that out we’d need to be able to reproduce this.
Looking at the isocurves on that surface, you can see straight away there’s something wrong with it:
-wim
please post the gh file including the portion of definition that includes the loft, the curves used to generate it, and eventually how those curves were created
OddLoft.gh (8.0 KB)
Here you go. The loft generation from simple lines
Hej Timo -
Thanks.
→ RH-86011 Grasshopper: Straight Loft Creates Wonky Srf
-wim
I ran into a similar issue, the hack to fix it was drawing a circle around the center point (left in your view) of, say, 0.001, or twice the document tolerance, trimming the surface with that circle, and then proceeding with the rest of the design.
Since the straight loft seems to not properly work with a list of curves where some share endpoints, I suggest to try a different approach: get the pairs of consecutive curves, use the ruled surface component to create correct untrimmed surfaces between tha pairs and eventually join the surfaces
OddLoft_rev.gh (12.8 KB)
Exactly correct - When printing something like this that is based on a Loft surface that comes to a point I fudge it by making the top control curve a tiny circle. My printer has a much larger tolerance than a production NC machine tool so my top circle is something like .05 mm diameter.
It is a pure modeling (Rhino) issue though, system didn’t like a surface that converged to a point. Wim & Co will get it figured out.
