I think it is just the same surface rotated 90 degrees then offseted and then filleted at two edges. Because you mainly take two lines of cylinder to get developable surface. So you are lofting a line rather than cylinder, just have to deal later with ends.
Hi Charles - it seems maybe the path ought to be a 1/4 turn helix. Here’s my go at it…
Cyan = Fin of the green helix curve on the large cylinder. The fin edge is used to drive the Sweep1 of the small cylinder diameter to make the blue ‘caps’ CP_CylinderChallenge_PG.3dm (60.9 KB)
That’s not quite it either… it’s maybe, the path of the diameter of the end circle, but does not account for the rest of that circle. Hm - I’m not sure the swept volume has a linear ‘cap’ surface in the short direction - it might have a crease in it.
Even if that is accurate for the diameter, the cylinder at intermediate positions only conforms at the dialmeter:
just take the mesh as reference for a surface model. This is a common problem in engineering. You get a point cloud/mesh and you put surfaces on it. And no, there is no algorithm which solves these tasks in a satisfying way.
I was able to go to voxel size of 0.05. Each time you divide by 2 you multiply the.number of voxel by 8.
You could also unweld mesh to have a better looking. You could play with adaptative to lower the faces number …
Not a great help to get a super shape but it is a start.
more resolution does not mean getting a cleaner result. I would even do the opposite, reducing the mesh vertex count in order to make the point-surface-deviation analysis faster. I think you can see the tendency for a linear movement with far less points. Depending on your acceptable tolerance, I would value simplicity over accuracy.
My apologies in advance if I am oversimplifying this or misunderstanding the intent. I’ve created an extrusion, filleted the ends to achieve a cylindrical “cap”, then twisted the poly surface by 90º. Result attached.
I’m afraid this simplification does not work. If you transpose a circle from the top of the original cylinder onto the twisted form you will see that the latter has a distorted end. And if you project helical paths from various points around the circle to denote those points’ movement as they twist towards the final circle you will find that they do not fall on your surface.