I want to create a basket from arrayed polygons by applying the pipe2 command. I am using the latest v3 beta, and the pipe2 was receiving OD=1, ID=0.

Strangely, only a couple of the polygons are piped, the others won't. I can't see a difference between them, but something is not working.

On a sligtly linked question: I need (for printing) a volume and used pipe. But if I wanted to have a square pipe or an I-beam instead, what command would I use?

Thanks a ton!

Same as you ! Some are working other Not!
Very mysterious! :)
So wait Michael answer!

When you separate a closed curve that work, when you re-join it that work not!

Maybe it's better to draw one then array it ? ;)
It's more speedy on my very old computer!
I have used the Polygon Function : that works !

C'est sont les vacances ... fainéants ! :)

I am just hoping that I am not making a fool out of myself (although I have some great tendency in doing so).

Another strangeness in this model is that the two rows in east and west, those that complete from top to bottom, have surfaces created within the pentagon.

And have you tried to select a single pentagon? One that is not piped?

Very strange thing. But I guess I need to add, for the completeness of information, that this model is made using the Paneling Tools in Rhino v4, brought over using cut-n-paste. I have never had any problem going back and forth between Rhino and MoI, and I assume the issue is in PT.

I should certainly have said this in my original message§ I just hope I didn't cause a huge waste of time for investigation a problem that is made elsewhere. Very sorry! :(

With an outer radius of 0.1, and an inner radius of .01, Pipe2 does work on one of the nonplanar pentagons.

< < And have you tried to select a single pentagon? One that is not piped?
a single who are not working is not working when it's selected alone!

All pentagons are not planar but normally a closed polyline or a cloded curve even not "planar" must makes a pipe!

<< C'est sont les vacances ... fainéants ! :)
Hélas pas encore! :(
Mais bientôt! :)

Pipe2 works with a reduced radius.

Seems like a good candidate for paracloud program?

<< Seems like a good candidate for paracloud program?

I would say Flow ? ;)

Paracloud : I wish I could. This seems to be a terrific piece of software. But not within my allowance ;)

Good find that smaller radii help somehow. Although they create some open, and strange surfaces.


Flow : Not sure how I could unroll the surface to fill. I am attaching the basis of all this.


Anyway: Thanks guys for getting into this. This place here rocks seriously! Thanks!

Hi Ditto,

> Strangely, only a couple of the polygons are piped, the others won't. I can't see a difference
> between them, but something is not working.

It's difficult for Sweep (which Pipe is based on, it's just like a macro that does sweep with a circle as the profile curve), to handle path curves that are warped in 3D space (meaning not planar) and also have sharp corners in them, which is what many of your path curves here have on them.

The way sweep works it does each segment of a sharp cornered path individually and then tries to extend the segments and cut them with one another to form mitered corners. That "cut against each other" step becomes difficult on non-planar warped paths because the sweep along a curved path generates a kind of twisting and banking effect of the profile as it travels along the path and so it's easy for the surfaces to not actually cleanly intersect with one another. Check out here for a more visual explanation on the difficult part of this: http://moi3d.com/forum/index.php?webtag=MOI&msg=4937.4

It should work ok if your path is made up of all line segments instead of slightly bent curves though - when segments of the path are lines it's able to cut each piece by a plane to make the miters.

Your paths are so barely curved that it would probably not be a very dramatic change in shape to have all straight lines for them rather than the very slight curves that you currently have.

The ones that ended up working ok for you were planar or happened to be very very close to being planar.

Hope that explains some of what you ran into.

So to fix it you would either want to have all straight lines on your paths or probably do it all on a flat planar pattern and then do a flow on that to apply the whole set of pipes onto the curved surface rather than building pipes in the curved position to start with.


> But if I wanted to have a square pipe or an I-beam instead, what command would I use?

You can use Sweep for that - it's the general version of Pipe, and in fact Pipe is not anything more than drawing in a circle and doing sweep.

Check out here for some examples:
http://moi3d.com/forum/index.php?webtag=MOI&msg=5407.6
http://moi3d.com/forum/index.php?webtag=MOI&msg=3431.4
http://moi3d.com/forum/index.php?webtag=MOI&msg=4578.3

- Michael

Hi Ditto,

> Flow : Not sure how I could unroll the surface to fill. I am attaching the basis of all this.

There's a plugin called "UnwrapCurve" that can help with this, you can get it from here:
http://moi3d.com/forum/index.php?webtag=MOI&msg=5136.1

Probably use Construct > Curve > Iso to extract an isoparm curve somewhere around the middle of the surface, then use UnwrapCurve on that isoline to generate a line segment of the length of that curve, you'll then need to rotate that line to be horizontal and it will be the horizontal width of your flow base plane, do another UnwrapCurve on the vertical edge to get the height of the flow base plane, that should then help to reduce stretching.

Let me know if you need more help with using Flow here.

- Michael

Also re: Pipe not generating results - another step of what Pipe does is to generate an outer pipe surface and then an inner pipe surface and then do a boolean between the 2. When the pipes are not well formed because they're not mitered well that boolean step is probably ending up generating no output for many of those cases.

If you instead use Sweep you should get results on each profile, but you'll see that many of them are not getting miter trims on them (due to difficulty calculating miter intersections between 2 curved segments as described previously above).

If instead of Pipe you draw a circle and use Sweep, you'll get a result on every path but there will be a lot of extended pieces on failed miter cut areas.

To use Sweep instead of pipe just draw a circle of your desired radius somewhere off to the side (specifically it should be outside of the bounding box around the paths), like this:



Select it and then run Construct > Sweep, then at the "Select rails" prompt select all those path curves, that will generate a result like this:




But the problem here is that there will not be clean intersections between the extended portions of each path segment - that's just what happens on sweeps along non-planar path curves. I think that probably building the tubes all on a flat piece instead and then using Flow would probably be your best bet.

- Michael

Thanks a lot, as always, for your help and pertinent answers, Michael.

I have stuff to digest now. And try things.
Thanks again,
Ditto