# Sweep along a path through multiple cross-sections

I'm trying to make sweep along a path through multiple cross-sections. Finally got to the point where I managed to place objects along that path in correct orientation - almost. Still have some glitch or some fault in my nodes. It does place shapes right, but sometimes shape turns around 180deg. on Z axis when changing position along curve. Now question is how could I make sweep of these forms along that path.

If anyone need blender file to take a look - let me know, will try to send it. and it is on 2.81a blender and currently latest sverchok.

• If not already aware, you may wish to make use of blend-exchange.giantcowfilms.com Jan 28, 2020 at 15:17
• all profiles would need to have the same Vertex count, or at least the last profile (looks like 4 vertices) would need to have several double vertices on each of the 4 points (or subdivided so there are vertices linear interpolating the 4). I'll show an example below, and try to closely match yours Jan 29, 2020 at 12:26
• @batFINGER has given a couple of non-Sverchok answers here and here which may be of interest to you Jan 29, 2020 at 13:12

## 1 Answer

i'll further update the answer if you upload a demo blend with those shapes. I'd like to give you a nice answer.

For now, i'll clarify what i've said in the comment, with an illustration. For predictable results I recommend making sure all profiles have the same vertex count. There are two ways to do that.

subdivide the square profile.

or, double up on the destination vertices.

notice that the locations of the vertices in this "doubled up" example will produce some undesirable twisting in the end result.

One simple way is to interpolate both UV (slices between profiles) - without a path or trajectory". Notice how the extrusion goes exactly through the profiles too.

In the above example you must position and rotate the profiles in such a way as to achieve minimal stretching. Sverchok's Object In node interprets each Curve as a list of Vertices (the vertex indices are sequential and stable from Curve objects) and we interpolate between the list of resulting profiles. Get the .blend on this issue

• Can you loft 'normal' to intermediate profile vertices? In practice, I think this would mean that the vertices adjacent the profiles would be parallel to those profiles. Feb 3, 2020 at 14:06
• I'm not sure exactly what you mean. Feel free to ask a detailed question on the issue tracker with plenty of visual aides to narrow down the core. We have Bend profile Surface and Path nodes, with documentation. Feb 3, 2020 at 16:18
• i hadn't really thought about this, but i suppose when using a Path/trajectory for the loft, it lets you supply fewer profiles to achieve a particular result. Maybe try the nodes mentioned above Feb 3, 2020 at 16:28
• I feel like I've exhausted my question quota, but maybe I'll try to illustrate the point - if it's not clear. Feb 3, 2020 at 16:51
• i prefer to receive questions that can either be answered by a solution or a new node, than to see people migrate away from sverchok :) often this does mean that we need people to spell out their needs, and then we decide if we can accommodate effectively. Feb 3, 2020 at 17:55