Hello,
I think some of you may have encountered this before — when the bridge geometry is slightly twisted and lies on a curved path that isn’t on a single plane. The rebars can shift away from the central position, and when adjusting the “On Plane” parameters, there can be unpredictable movements. So, I usually set them to 0 to make things easier to manage.
However, even without changing any input parameters, the rebars still jump around every time I enable or disable the Rebar Group component.
Do you have any idea how to fix this so that the rebars stay fixed in place after toggling the component?
Thank you,
Hi Tung,
A bit tricky to answer without having the model/script to check but I think I know what you mean. I have had the same issue as well, but I don’t think it’s a GH-Link problem rather a Tekla Core issue.
Again, since I don’t know how the bars have been modelled I can’t only make assumptions. If you have not already considered tapered rebar groups then I would strongly suggest using them and also like you say when the bridge is twisting and there’s not a clear plane from which you can use a cover from then offsetting the lines in Rhino and then feeding in centerline with 0 cover is probably the best solution.
Not sure if this helped but that’s the best I can do with the information given.
Cheers,
Oskar
Hi Oskar,
Thank you for your answer.
I’ve also considered adjusting the curves and moving them to the center to avoid using From Plane and End Plane. I’m not entirely sure whether the issue comes from GH-Link or Tekla Core, because when I manually move the group up or down in Tekla, the rebars don’t jump around. This mean that with the same geometry, modeling it manually in Tekla doesn’t cause any issues.
I’ve attached a geometry example in the GH file, and just to note, the unit I’m using in Rhino is “meters”.
Thank you,
Tung Quach
RebarIssue.gh (15.4 KB)
Hi Tung,
Using your lines, everything seems to be working just fine when I add a On Plane cover.
Sometimes I shorten the curve instead of adding end cover since that might screw it up (sometimes). Also make sure that you’re on the latest Tekla- GH link. 1.19 currently.
Last thing to mention is that on these long bars it’s worth adding more control points to make sure that you’re not hitting the limit and the shape is getting simplified due to the number of control points.
Hope this helps!
Hi Oskar, Thank you
Interestingly, I also tested it on another computer, and the rebars still jump with the same geometry. However, it seems the issue is partly related to the type of curve. I slightly modified the curve and increased the division from 8 to 15 points — this reduced the jumping behavior, almost to the point where there’s no visible change.
But this is more of a workaround by changing the input curve, rather than solving the root of the problem. So I still think the issue is there. I’m also wondering why it works fine when modeled manually, but changes occur when using the Rebar component — ideally, it should behave the same as native Tekla modeling.
Anyway, thanks again! I’ll continue investigating this further.
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