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I am trying to make a continuous loop from a few arc curves but when I do a curve to mesh with a curve cicle, the end faces dont align. This example has two arcs but I actually want to do 10 or more.

enter image description here enter image description here enter image description here

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  • $\begingroup$ Perhaps if you described your goal rather than your current approach we might be able to work out a better way to solve your problem? $\endgroup$ May 8, 2022 at 22:58

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As quellenform commented, multiple splines won't align, but you can recalculate the ends or even the entire thing.

The reason for the misalignment is that the direction used to generate a profile curve in a point of the main curve is the interpolated value from the two adjacent edges, but in the ends of the curve there is only a single edge.

If you or someone else wants a Geo Nodes to fillet a curve with a true arc, here's one I did:

Geometry Nodes arc fillet

Arc fillet custom node

Arc fillet no misalignment

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  • $\begingroup$ This is perfect, looks like this is what i was looking for, Thanks. $\endgroup$
    – Roel Deden
    May 9, 2022 at 8:28
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I love Hulifier's interpretation of my idea, but what I love even more are simple solutions:

Why would you calculate the angle of the ends when Blender has already done that for you?

This image shows four arcs that were extruded using Curve to Mesh:

enter image description here

After all, since we have all the necessary information in hand when creating the arc and the profile, all you have to do is the following:

  • Calculate the angle of one segment
  • Select the points of the mesh at the ends
  • Transfer the positions of the points of the second profile segment (because it already has the correct rotation)
  • Rotate the positions of the end points according to the angle of a segment

enter image description here

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  • $\begingroup$ Why not, Indeed? $\endgroup$
    – Robin Betts
    May 9, 2022 at 19:17
  • $\begingroup$ @RobinBetts Why not a simple solution, or why not calculate everything manually? $\endgroup$
    – quellenform
    May 9, 2022 at 19:33
  • $\begingroup$ Why not be simple? :D I'm just about to post an inferior answer : $\endgroup$
    – Robin Betts
    May 9, 2022 at 19:45
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if i understood you right, you just want them to align, and not "one" curve, so you could just increase the resolution of your arc to a high number and the align pretty well:

enter image description here

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  • $\begingroup$ Yes it is better but not perfect. $\endgroup$
    – Roel Deden
    May 9, 2022 at 8:27
  • $\begingroup$ yes of course, because the arc will be divided into pieces (defined by resolution) and Blender calculates from that "piece" the angle so it had to be infinite to get a perfect right angle. But - just my opinion - if you make it high enough you won't see it in render...and you can push it really high... ;) just my opinion $\endgroup$
    – Chris
    May 9, 2022 at 8:30
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I suppose you could wheel out the ol' Curve Deform group (simplified a bit), and use it to deform a prism of an appropriate length, given arc-span and arc-radius, then rotate the whole thing to the start-angle:

enter image description here

Here used to demo with the fixed default resolutions illustrated above:

enter image description here

enter image description here

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  • $\begingroup$ I am always amazed at the variety of solution possibilities when Geometry Nodes are in play +1 $\endgroup$
    – quellenform
    May 9, 2022 at 19:59

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