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Road from curve

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Sybaris
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Hi everybody,

I'm trying to create a road from a 3D curve. I tried PolyExpand, Sweep and PolyExtrude. They basically work but the result is twisted in (more or less) random directions. I'd like to have every segment parallel to the XZ plane.
What am I doing wrong? Or how would I do that?
HIP file is attached.
Thanks in advance!

Günther

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Attachments:
Staatz.hiplc (128.7 KB)

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Aizatulin
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Hi,

PolyExpand works, but only on planar curves. Your curve is not planar but you can make temporary planar by setting the y to 0. After Expand you can write the original y-value back.

Attachments:
Staatz_planar_y.hipnc (133.6 KB)

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Sybaris
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Wow, that was quick! And even better: it works!
Thanks a lot Aizatulin!
And it makes me getting deeper into AttributeWrangle! ;-)
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Sybaris
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Sorry to fire up this thread again.
Everything's fine with PolyExpand but I also need more complex shapes and that leads me to sweep and there the same problem persists. The shape is copied along the curve but it is also twisted, that means it is also rotated around the z axis.
Is there a simple VEX snippet that sets the z rotation to zero?
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Aizatulin
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Setting the up vector (v@up = set(0,1,0)) in a point wrangle should work.
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Sybaris
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Hi Aizatulin,

funny, because that's pretty close to what I found out! :-)
I used "@N.y = 0;"
Although I'm not sure WHY it works...
But works perfect now with any shape.

Thanks again!
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Aizatulin
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Sure

on curves v@N is usually the tangent and v@up determines the up vector. The real up vector will be calculated automatically and it will be perpendicular to v@N with closest angle to v@up (afaik).
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Sybaris
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Thanks for the explanation!
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