Self-Intersecting curve extrude

Rhino Rhino for Windows
1

Hi everyone. I have a set of curves that I got via the following steps:

  1. A drawing from an artist that looks like this:
  2. I livetraced every color in illustrator, and exported the curves as a dwg.
    When I import it in Rhino, it looks fine, like this:

Now, each color represents a layer of laser-cut wood. The problem I’m having is that most of the generated curves appear to be self-intersecting, so when I try to extrude the first layer, I get this result:

It’s not a problem of a missing cap, it’s a badly generated object.

I tryed to scan the curves for obvious self-intersects, but couldn’t find any.
I have to do 10 of this trees, does anyone have any tips or ideas?

thanks!
Tree.3dm (671.3 KB)

2

Hi Alejandro,

Have a look at the command _CurveBoolean
( http://docs.mcneel.com/rhino/5/help/en-us/index.htm#commands/curveboolean.htm?Highlight=curveboolean )
It is a great tool to clean up curves with small loops that create selfintersections, typical for curves coming from Illustrator.

HTH
-Willem

1 Like
3

Hi Alejandro
Draw a Line normal to cplane like binary end try sweep1
Ciao Vittorio

4

Hi Willem
I tried curveboolean and it fixed some of the self-intersects, but some remained.
Anyway it is a good start and now I have to find less of them.
Thanks a lot!

5

I’m not sure curveboolean fixed anything for me, but the problem remained and I don’t know what the next step is.

How do I identify where this closed curve is self intersecting?

self-intersect.3dm (137.6 KB)

6

IntersectSelf should put points at the self-intersection spots. Yours shows up as one point, but it’s at a corner and I don’t see anything wrong there immediately. But if I turn on control points, the corner there as well as the one above it have two control points at the joint, not just one. I window sub-object selected that segment and deleted it and made a new line to replace it and joined. No more self-intersection…

1 Like
7

Thanks, nice to see that a command for that was added since this thread was created!

But yes, that intersection was weird, because it created the shapes just from offsetting and then trimming three polylines and a circle…