common perpendicular line between two skew lines

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Permalink Reply by Danny Boyes on March 24, 2014 at 9:58am

[Curve Proximity]

Permalink Reply by qiushi on March 24, 2014 at 10:01am

ha!

Thanks!

I saw your older discussion as well!

That is it!

Permalink Reply by qiushi on March 30, 2014 at 2:00pm

Hi Danny,

I found it works in some situation(all the lines are long enough), but when one skew line is not long enough, then the line found is not the common perpendicular line between them.(it is perpendicular with the two lines at the same time.)

actually,I want to do this.How can I guarantee all of these intersect lines perpendicular with each other? any idea?

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Permalink Reply by Roberto Narvaez-Rodriguez on November 4, 2014 at 8:33am

Probably, it is too late for qiushi, but I have just seen it and posted it just in case someone else may find it useful.

To determine the common perpendicular to two skew lines, I would always use "line-line intersection"(mathematical) component. Here is the explanation:

"Curve proximity" component only work with physical curves (not mathematical). The output points are the closest from the two physical segments represented. Therefore, when the common perpendicular to the two skew lines intersects the physical segments, the result is right. Picture 1.

  Picture 1

However, with "Curve proximity" component, when the common perpendicular to the two skew lines does not intersect the physical segments, the result is a pair of points which are the closest from the two physical segments represented, but they do not coincide with the extremes of the common perpendicular. Picture 2 (the right result in Rhino is drawn in black).

Picture 2