Offset fail

I extracted a number of contours from a brep and am trying to offset those curves .25". When I set the offset distance to .25" a couple curves fail, when I offset it .32" it starts working again. Any idea what's going on or maybe a cleaner way to offset to prevent this problem?

Attachments:

offset work.PNG, 181 KB
offset fail.PNG, 176 KB

Replies to This Discussion

Permalink Reply by Jack D on November 14, 2017 at 9:44pm

grasshopper file

Attachments:

contour offset.gh, 30 KB

Permalink Reply by Joseph Oster on November 17, 2017 at 9:55am

I don't see any curve failures in this code you posted? 13 inputs, 13 outputs, all "Closed Planar Curves". I can get it to fail by using negative distance (expression "-x" on the 'Offset D' input.

The Clipper plugin 'PolyOffset' produces both +/- offsets; use the 'H (Holes)' output to get the inner offset. It will fail too when the distance is greater than the space available, somewhere near ~0.4 in your example.

Permalink Reply by Laurent DELRIEU on November 14, 2017 at 11:28pm

You can test clipper on food4rhino

Permalink Reply by Jack D on November 17, 2017 at 9:29am

What if i need to offset in one direction only?

Permalink Reply by Jack D on November 17, 2017 at 9:30am

Anyone have any ideas? I can't offset a set of curves without some of them failing and it's driving me crazy!

Permalink Reply by Federico Marzano on March 9, 2019 at 6:15pm

Hello, i have a question about offsets in grasshopper. In this example i am doing an offset in grasshopper with a closed curve and it fails. Then i do the same offset in rhino with the same curve and it works perfectly.

Anyone knows why this could happen?

Attachments: