offset surface boundary inward failed

I want to get the inward offset of the following two curves:

The workflow attached can get the inward offset surface, but the normals of the two surfaces are not the same, even if I flipped the normal of one of them:

Also, as the offset distance increases, one of the surface will fail:

May I ask:

1. why the offset function is not working for one of the curves beyond certain distance?

2. If the normal of a surface generated by the "boundary surfaces" component is dependent on the order of the points of the boundary curve, how can we "flip" the order of those points?

Thank you.

Attachments:

offset surface edge _v01.gh, 10 KB

Replies to This Discussion

Permalink Reply by Grasshope on September 12, 2017 at 2:36am

OK, I found that the "flip curve" component can be used here to reverse a curve:

But I still don't know why the offset is not working when the distance is larger than 1.2 in this case...

Hope you can kindly advise.

Attachments:

offset surface edge _v02.gh, 9 KB

Permalink Reply by Grasshope on September 12, 2017 at 2:45am

... workflow further simplified.

offset not working for one of the curves when distance is 1.1:

offset is not working for both curves when the distance is 1.8.:

May I ask what is causing the problem here?

Thanks.

Attachments:

offset surface edge _v03.gh, 7 KB

Permalink Reply by Hyungsoo Kim on September 12, 2017 at 4:20am

Hi.

You can use "Clipper" plug-in.

Attachments:

offsetsurfaceedge_v03_re.gh, 9 KB

Permalink Reply by Grasshope on September 15, 2017 at 9:57am

Thanks, Hyungsoo, for your suggestion. The Clipper plugin works in this case.

However, it seems it cannot handle curves on planes in different height. The image below shows that the offset lines were projected to the same plane. May I ask if you know how to fix this issue?