I am trying to make several sweeps in grasshopper with a single rail and several sections. In this particular case it is in one rail/curve and a rectangular section at the beginning of the curve and another turned section at the end of the curve. The problem is that the sweep appears broken at a point shown in the image.
Any idea how to fix it?
I have changed the absolute tolerance in rhino and still the same problem. If I bake the grasshopper curves and make a sweep in rhino I get it right.
Thank you very much in advance.
Note: the curves are created by projection on a brep.
don’t know if rebuilding the curves is an acceptable solution for you
Most probably your brep surfaces aren’t tangent.
As @inno suggests you will have to rebuild your curves. If possible, I would fix the problem where it started = rebuild the sections used to create the brep so that they are continuous. If that’s not an option, rebuild the projected curves.
¡¡¡¡Thanks so much guys for the input!!!
Thank you very much indeed!!!
I have reconstructed the curves by setting true in preserve the end tangents of the curve. Is it necessary?
I think the real problem comes from the surface on which I project the curves. I don’t know how to make the cone and the flat surface tangent and form a single surface when doing the Brep join?
I also send you the grasshopper file in case you can help me with it.
20220208_NON_CONTINUOUS_BREP_v#00.gh (414.1 KB)
Thank you very much in advance for all the contributions!!!
you can use revolve to get a single surface
end tangents may not be necessary, where do you get these curves from?
I can’t use a REVOLVE because I need to join the conical surface with the corresponding flat surface as indicated in the grasshopper file.
The reason is that then I am going to make a RECTANGULAR ARRAY where this column is part of many more joined to each other hence the curves end up square.
Here I show the rectangular array and the detail of how the beams would have to be next to each other.
you could get the very same rectangular array by using the conical surface trimmed by the very same squared boundary, like this
Sorry for taking so long to answer but I’ve been very busy.
First of all thank you very much for the contribution @inno because it has been very useful and I think I have it definitely. I’m sending you a screenshot of the final image.
Regarding the Sweep1 that form the columns, I have had problems with the rectangular sections because they were rotated and not perpendicular to the rails as they should be. I think it is due to the twisting of the curve itself. Here I send the grasshopper file on how these sweep1 would be created by rotating the final PFRAMES due to the torsion.
Is it possible not to rotate the PFRAMES and that the sweep1 come out well, that is to say that the torsion is 0 in all the curve or how it would be done? Any idea?
how are these curves generated?
@inno I send you the grasshopper file where I show you where the projected curves come from. They could be taken in a more direct way or simply in another way but this is one. I have doubts in how to solve the torsion of the curves.
I really appreciated your advice on how to solve the problem. Thank you very much.
there are many things going on at the same time, for instance:
when you evaluate the tortion along the curve, you can notice that some curves are flipped (meaning that once you define what you consider “start” and what you consider “end”, not all the curves share the same direction)
this group just checks -for each curve- if what is considered “starting point of the curve” has a distance from the XYZ origin less than 500 units: if that point is farther than 500 units, it just flips the curve
one important note: this is not good practice, it’s just a patch
in order to understand why and where your curves got flipped, you might want to go back in the stream (like salmons lol) find the point in your definition where that thing happens and fix it from the root (in such a way you can then delete this patch and keep on going with a clean, streamlined and lighter definition)
one way to draw the shape you are looking for might be through Sweep2, like this:
the two rail curves are generated by projecting the planar curves on two surfaces, which are the offset of the original one by +/- half of the beam height (please note that things that are easily created on Rhino canvas, like these beams, might not be that easy to be produced also in the real world )
Thank you very much @inno for your contribution.
I don’t know if creating a Sweep2 with two rails is the solution or also creating a LOFT with several rectangular sections along the curves is better.
In the end, I think that the idea is to create new ways or paths to achieve the desired end. Everything has infinite or almost infinite ways to reach the same result.
Thank you very much for your help!!!
It has been very instructive