Question

Constructing 3D arcs with 3D points

  • 3 July 2019
  • 1 reply
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Hello,

I'm struggling with making a certain module: I have 2 3D points with a certain z-value and i have a 2D arc "connecting" them.

I am now trying to build a module which would make a 3D arc or a generalized 3D polyline using the z values of the 2 points given.

At this point I'm just doing this manually but an automatisation of this process would certainly increase my workflow.

Can someone just point me in the right direction so I could solve this.

Thanks,

 

EDIT: The two 3D points do indeed have a different value in Z.

1 reply

mark2atsafe
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Userlevel 4
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It depends on if your 3D points have the same z value. If so, use the Offsetter transformer to just raise the z value of the arc.

If the 3D points have a different z value... that's more complex. There's a 3DArcReplacer transformer, but I don't really think that helps. It looks to me like it just creates an arc-by-centre with a fixed z.

This seems really difficult. I can only think of two possible methods.

1: Figure out the angle/bearing between the two points. Stroke the arc and rotate it (with the 3DRotator on the x or y axis) using the calculated angle. That would give you a 3D line approximating the arc.

2: Stroke the arc and use the SurfaceDraper to align it to the 3D points.

I think the first method would produce a better result, but I'm not totally sure how to calculate the rotation. The second method is simpler but the results won't be as good.

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