Lofting curves with different shapes

[gon123]

Hello all,
I am a beginner using Rhino and Grasshopper and I am having some trouble lofting some curves.

I am trying to loft 5 parallel curves where 4 of them have different shapes and it keeps connecting to the wrong points.
I made sure that all curves have the same direction and number of control points (as suggested in other topics where people had trouble lofting), but I believe that because the curves have different shapes, even when I correct the connection between control points on one side of the curve, another mismatch between control points occur on the other side of the curve.

Here are some pictures of the problem I am having:

I manually corrected the CP connection at this corner but as you can see the other corner is twisted.

This gets even worse at these locations:

Any tips on how to fix that? I believe that something like ‘connecting to the nearest CP on the curve above’ would fix this issue but I am not sure how to do that on Grasshopper.

Thank you!

lofting.gh (57.2 KB) loft_trying.3dm (2.9 MB)

[Kaushik]

HI gon123,

From a (very) quick look at the files, I can see that the control points are misaligned (or, aligned in a non-favourable way). I tried lofting the curves directly on Rhino, and got the same result - which only proves the point.

I would suggest that you create the PolyLine on each floor, with control points, matching the floor below(or above, depending on your loft sequence), and in places where the profile changes, just make sure the count of points are equal.

I’ll try to attach a solution file after work.

~ ~ ~ ~ ~ ~ ~ ~
Kaushik LS
Chennai, IN

[ME_Mark]

Use the curves that you created earlier and try some loft options: lofting_ME.gh (44.9 KB)

[gon123]

Thank you for the help Mark, the loft is better than it was before but I am still having some trouble with it.

It seems to work fine like that but the problem is that the whole purpose of this grasshopper model is to create a parametric model where I can change the format of each floor freely.

So for example, the loft is connecting these two points over here and everything seems to be fine:

But if I increase the radius of the fillet on the third floor, because the same two points are still connected, this strange twist happens:

I believe that finding a way of connecting the red circle on the bottom with the blue circle on the top floor will fix the issue.
That is why I think something like the loft always connecting to the closest point would work fine but I am not sure how to model that.

[gon123]

Hi! Thank you for the suggestion. I tried aligning the control points of each floor (also searched the forum for solutions on how to do that) but I couldn’t find any.

Any tips on how to do that?
Thank you!

[isabellaeloy.be (b.eloy)]

I think it is already solved, but i’m gonna share what worked for me based on what Kaushik said. I’m not sure it was exactly what he said, but solved my issue: