Problem with "mirroring" variable pipe

Hello, i have a poly line that is mirrored by x axis and i want to create a variable pipe that i can controll the radius at point for example 12, 5 and 0 ( see attached image). I want to be able to just pick those points in the panel. Also the pipe splits at some points…

parametric kite (65.2 KB)

The model is too complex for me to wade through in depth but why don’t you create one half the handlebar and use Mirror to get the other?

Because i want them to be connected in the middle.

Hows about this?

parametric kite software (55.2 KB)

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I made some small changes and it sorta looks right but there are small spheres at some of the joints that don’t look right at all? The model looks more complex than it needs to be.

parametric kite (57.1 KB)

Why polylines instead of interpolated curves?

Or the smoother interpolated curve version:

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that is almost it but it is not connected in the middle, i want to just pick numbers on one side because number of these points can change and i want it to be more automatic.

This script is going to be used for designing kitesurfing kites and i need to be able to change everything thats why it is complex, i haven’t clead it yet becasue it is 1/6 of the whole thing. small spheres are just to help me mark important point for later. thank you for this one. Can you explain to me why the pipe is acting weird in those two points?

OK so just specify the one side and use those to generate the other side, not very difficult:

What do you mean '‘it isn’t connected in the middle’? It’s a single untrimmed surface so by definition it is connected. What isn’t connected to you?

Sorry, it was connected, i probably opened wrong file. I did as you did with some small change, but there is a new problem and your file had it also. In the middle of the pipe at point 12 the pipe is a bit croocked and there is no circle visible like at all other points. Do You know how to fix that?

parametric kite (57.2 KB)

How is the pipe crooked? Looks spot on to me.


As for the ring not showing, not sure why that is but it looks to just be a weird visual thing. If you bake the BRep to Rhino and check the ghosted view you’ll see the surface edge there:

When you look at the connection at the bottom of point 12 you can see that it is a bit to the right. And on the top I marked with blue it is just a bit crooked if you zoom in, inrhino. Maybe just a display problem as you said.

Right gotcha. It’s because you’re using a polyline rather than a smooth nurbs curve. When you pipe a curve, the component generates a circle on a plane with its origin on that point and normal aligned to the curve direction. For a polyline, if you pipe at kink points, your curve changes direction, so the pipe component has to pick a normal from the two directions it has at that point. So, your pipe is correct, but it is parallel to one of the curve segments and not the other.


What I expect you want it to do is find the average normal between the two curves and pipe to that. That can be done but you’ll have to do it manually. Or, just use an interp curve instead.


Exacly. it is really weird to me why it works on any other point but it doesn’t in the center one

Anyway, thanks for your time. Now that i know it does not want to work this way i will just generate the center circle of the pipe conect it to the right side and than mirror it, maybe it will be simpler.

What’s the unit system of this file? Feet?

Well, anyways, I simplified your sorting of points and t parameters so you can use an interpolated curve.

parametric kite (75.7 KB)

I use cm. I solved my problem already but thank you for your time. I need to use a poly line because i need straight segments.