Perpendicular Lines on a Curved Line?

Hi,

I have a really annoying task ahead of me, hope you can help?

I have a curved line with a series of points placed at different intervals. I would like to load all the points and draw perpendicular lines at each point location.

I can do it in rhino manually so I figure you can also write a grasshopper script as well. Everything i have found online draws perpendicular lines based on dividing the curved line.

Rhino Process:

- Start with a curved line with points placed at different intervals along the line.

Perpendicular lines

- cmd: Line

- option "Perpendicular"

- Click and draw line at the point locations

I have around 100 points and will need to do this task multiple times. So the hours will clock up if I need to do it in rhino.

I have an attached rhino file which shows what I am trying to do.

Thanks a million..

Liam

Attachments:

PerpendicularLinesOnCurve.3dm, 197 KB
Curved.png, 9 KB

Replies to This Discussion

Permalink Reply by Luis Fraguada on December 9, 2012 at 4:06pm

use the Curve Closest Pt to get the parameter on the crv where the points are. This allows you to evaluate the crv to get a tangent. Here I rotate that tangent vector 90 degrees. You could also use a perp frame at that curve parameter. In that case the x component of the construction plane will be opposite to the directions of the lines in this image (or similar to rotating by 180 degress).

Permalink Reply by liam eastop on December 9, 2012 at 5:06pm

Thanks Luis for your quick reply, you saved me hours and hours of work. I modified the output to suit and it works perfectly. I am using it to layout mullions. Here is the modified version, bit messy, totally new to grasshopper.

Attachments:

GlAZ.png, 91 KB

Permalink Reply by David Rutten on December 9, 2012 at 4:07pm

The Curve CP component will find the point on the curve closest to a point in space. Unless the point is 'beyond' the curve, that projection will be perpendicular.

David Rutten

david@mcneel.com

Poprad, Slovakia

Permalink Reply by liam eastop on December 9, 2012 at 5:06pm

Thanks David, I ended up using Luis response.

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