2 Intersection points

Hi,

does anybody know, why I get two intersection points here instead of one?

I've got one surface and one intersecting line but I get 2 intersection points. If the line is moved to a slighlty different location the intersection works fine. This model is an extract of a much larger definition where a few hundred lines intersect with the surface and all seem to work fine.

The funny bit is that sometimes I get an additional point and sometimes it works fine. i.g saving and reopening the file.

Many thanks,

Attachments:

TwoIntersectionPoints.jpg, 121 KB
TwoIntersectionPoints.gh, 189 KB

Replies to This Discussion

Permalink Reply by Hannes Löschke on April 1, 2013 at 8:59am

Your surface seems to act strange. How did you create it? If you rebuild it with the same amount of U and V points, you will get a max. deviation of 2.5e-5 and only one intersection point.

Permalink Reply by Ralf Lindemann on April 1, 2013 at 10:01am

Hannes,

thanks for your response. I've noticed that the surface has a rather feisty character. It was build with EdgeSurfaces. 2 of the edges are compound curves (arc+tangentLine) and then rebuild. Could be the culprit.

I've used a different method now to create the initial curves and created the surface again. Seems to work. Thanks for your advise to rebuild the surface but in this case I've tried to avoid rebuilding it with deviation. I'm running into other issues with it.

Thanks again.

Permalink Reply by Hannes Löschke on April 1, 2013 at 2:16pm

EdgeSrf is a rather random way to define a surface. Can't see how rebuilding that surface has any effect to the target precision as a target isn't really defined in the first place

With 4 curves I'd rather sweep-2-rail the surface...

Permalink Reply by Ralf Lindemann on April 2, 2013 at 3:54am

Hannes,

You are absolutly right about EdgeSrf. It's really random and flips surfaces randomly around etc. I shouldn't have used it in first place. It was just a "quick and dirty" way at some point without having to bother about curve directions and right order.

You're probably also right with rebuilding the surface. But I do get a tiny deviation, also at the edges, which is not what I want if I can avoid it. I've spent some time sorting the edges and build the surfaces with Sweep2.

Thanks again.

Best,

Ralf

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