I tried to create sweep objects via polycurves to build a structure system. However, as shown in my snippings, all the sections at the ends of my sweep objects just deviated.
It seemed that the orientations of these sections didn’t follow the tangent vectors on the second curve. And I just wanted the orientations of the sections at the ends of the sweep objects to follow the tangent vectors of the second curve as what I did for the first curve. How can I align or control the orientation of the sections at the ends of those polycurves (or sweep objects) in order to achieve the correct sweep objects?
I’ve uploaded my example .3dm file and .gh definition.
I’ve uploaded my GH file. And I swept my sections via polycurves. So I just wanted to control the orientation of each segment of each polycurve in order to make the ends of those sweep objects follow the second curve.
Thank you for your advice. It seems that your code just confirm the beginning of a sweep object. And I’ve already finished it in my code. My problem is actually related to the end of polycurve which is located on the second curve(the curve where I drew a blue circle for one of the sweep objects on it)
This hack is a little better using HFrames on all four curves. The columns look correct, the cross beam at the top is the only part twisted? But if you consider that the pair of columns on each rail are not square to each other (or the same height), what do you really expect? A tapered beam section?
Thank you for your try! Although these two GH files still didn’t meet the requirement of the correct sweep objects to create structure frames, your solution just gave me a clue that there could be more than one sectional curves to control the orientation of sweeping. There’s possibility to control the orientation of every section of a straight line (P.S.: it’s the line of beam, not the second curve on the ground I mentioned before) in order to correct the final sweep objects.
Here’s a simple diagram about what I’m going to correct for my next step.
One of the problems is the corner of your structure. Another problem is that most of the three segment “rails” first and last segment are not perpendicular to the XY plane so horizontal plane can’t be used, or your oriented (steel) section has an incorrect cross section.
One small detail is your internalized cross section. You had it in one quadrant of the coordinate system. I’d choose to align the section symmetric with the X axis. The midpoint of the longest side on the origin. Orienting the section onto another plane requires just minimal effort if you do it that way.
Attached is a different approach. I created split surfaces with local miter planes.
All parts are closed. Not sure what you want to do with the corners.
Thank you for your brilliant solution! It really helps me to understand my GH file!
Actually I’m exploring an example of architecture structure. And I checked my architecture precedent related to this GH file again. I think my current approach is wrong. And I’m testing some new approaches which are different to my current GH file. I’ll try an approach related to Intersect - Contour in Grasshopper and see if I can generate some coplanar sweep objects.
Here are some pictures of my precedent by Kris Yao Artech:
Thank you for your great idea! Actually I think these spatial polycurves may not be suitable for C-shaped steel components. So I’m going to explore some other approaches. BTW, you can browse the images of my architecture precedent above.