.NET

## .NET

Contributor
Posts: 17
Registered: ‎06-30-2010
Message 1 of 4 (949 Views)

# Perpendicular Points on Polyline

949 Views, 3 Replies
07-19-2010 04:42 AM

Hi,

Is there is any way to get perpendicular points on both sides of a polyline at a specified distance?

I tried to offset the polyline (PL) on both directions as (PL1 & PL2) but still confused how to get a perpendicular point on PL1 & PL2 with a given point on PL.

Your inputs will be much appreciated.

Prajith.

Hi Friends,

Goal achieved using the below function.

Shared Function PolarPoint(ByVal BasePoint As Point3d, ByVal angle As Double, ByVal distance As Double) As Point3d
Dim x As Double = distance * Sin(angle)
Dim y As Double = distance * Cos(angle)
Return New Point3d(BasePoint.X - x, BasePoint.Y + y, BasePoint.Z)
End Function

Hi Tony,

I am not familiar with GetFirstDerivative() method. Certainly I will look at it how it goes.

Thanks a lot.

Prajith.

Distinguished Contributor
Posts: 147
Registered: ‎08-15-2007
Message 2 of 4 (942 Views)

# Re: Perpendicular Points on Polyline

07-19-2010 07:31 AM in reply to: Prajith76

Prajith,

Do a search for 'Polar' points in this Forum. This should provide you the answer you are looking for.

Josh Modglin
Valued Mentor
Posts: 305
Registered: ‎01-26-2005
Message 3 of 4 (934 Views)

# Re: Perpendicular Points on Polyline

07-19-2010 08:56 AM in reply to: Prajith76

You can use the GetFirstDerivative() method to get the direction

of the tangent vector at a given point on the polyline, which is

at a right angle with the perpendiuclar vector.

Contributor
Posts: 17
Registered: ‎06-30-2010
Message 4 of 4 (902 Views)

# Re: Perpendicular Points on Polyline

07-20-2010 02:07 AM in reply to: Prajith76

Hi Friends,

Goal achieved using the below function.

Shared Function PolarPoint(ByVal BasePoint As Point3d, ByVal angle As Double, ByVal distance As Double) As Point3d
Dim x As Double = distance * Sin(angle)
Dim y As Double = distance * Cos(angle)
Return New Point3d(BasePoint.X - x, BasePoint.Y + y, BasePoint.Z)
End Function

Hi Tony,

I am not familiar with GetFirstDerivative() method. Certainly I will look at it how it goes.

Thanks a lot.

Prajith.

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