I’m working on a model for a cast arm (see the attached images) and I’m running into a challenge with the Loft command. My design uses a mix of open and closed curves that I’ve organized along the Y-axis.
My goal is to loft all of these curves together to create a single, continuous surface that follows a clean, straight loft direction along the Y-axis.
When I try to use the standard Loft command on both the open and closed curves simultaneously, it fails. I know this is a limitation of the command itself, as it requires either all open or all closed curves.
Is there a workflow on GH that can solve this? I’m looking for a method that will:
Loft all the curves into a single, combined surface.
Maintain a consistent loft direction to prevent twisting.
Handle both the open and closed curves in one process.
I’ve attached screenshots. Any advice solutions would be greatly appreciated!
Maybe attach your actual GH file (internalize objects) so someone can look into it
*In the meantime:
Do you still have the original [closed] curves prior to becoming open? They can be useful: align + loft everything (as closed profiles) then split away that opening.
Ok - well then maybe having that mesh could be helpful.
First, as you intuit you must work with open and closed sections separately; however, you still cannot just ‘loft’ them in a straightforward way unless, for this case, you do some sorting, closing, aligning, and rebuilding*, to form the loft. After that you can rely on the points from the original open profiles to approximate the ‘hole’ profile.
*I see you’re using pufferfish (I skipped it), so maybe instead of rebuilding you can use its FitCrv component if you prefer, or increase the control-point count on the RebuildCrv component I used, for tighter curve-fitting, though maybe it’s not required?
*Note: what I did at first with the grafting and splitting of the tree is just from muscle memory, you can continue with your dispatching method for closed vs open crvs.
Lastly, prior to everything, I deleted all duplicate curves (quite a few) then re-internalized objects.
Honestly, more than just fixing the problem, your solution is givin me the perfect chance to dig in and see how it all works. I really appreciate you taking the time to help me learn.
Hey René,
I’d appreciate it if you could help me with doubling the seam (0.50) so we can proportionally split the arm before moving forward with the Voronoi
I’ve already divided the arm into equal parts by doubling the seam, with points at 0 and 0.5 on the crv. I internalized and extracted the crvs one by one. Actually I’m looking for a workflow that combines all of this into a single logic in Grasshopper, so I don’t have to manually internalize and extract each split…
