Creating Lines, part 1

Creating unassociative lines

If you need to create some unassociative lines (think old basic curves), you are in luck; there are 2 quick and easy methods to accomplish this. To create these lines you can use the curve collection's CreateLine method which has two variations: you can pass it two Point3d variables or two Point objects. A quick example of each method is below:

[vbnet]
'NXJournaling
'CreateLine example

Option Strict Off
Imports System
Imports NXOpen

Module Module1

Sub Main()

Dim theSession As Session = Session.GetSession()
Dim workPart As Part = theSession.Parts.Work

Dim markId1 As Session.UndoMarkId
markId1 = theSession.SetUndoMark(Session.MarkVisibility.Visible, "NXJournaling.com")

'create line given 2 point3d variables
Dim ptStart As Point3d = New Point3d(0, 0, 0)
Dim ptEnd As Point3d = New Point3d(-4, 5, -6)

Dim line1 As Line
line1 = workPart.Curves.CreateLine(ptStart, ptEnd)

'create line given 2 point objects
Dim pt1 As New Point3d(5, 5, 5)
Dim pt2 As New Point3d(-5, -5, -5)

'create point objects
Dim ptObj1 As Point
ptObj1 = workPart.Points.CreatePoint(pt1)
ptObj1.SetVisibility(SmartObject.VisibilityOption.Visible)

Dim ptObj2 As Point
ptObj2 = workPart.Points.CreatePoint(pt2)
ptObj2.SetVisibility(SmartObject.VisibilityOption.Visible)

Dim line2 As Line
line2 = workPart.Curves.CreateLine(ptObj1, ptObj2)
line2.SetVisibility(SmartObject.VisibilityOption.Visible)
line2.RemoveParameters()

End Sub

Public Function GetUnloadOption(ByVal dummy As String) As Integer

'Unloads the image when the NX session terminates
GetUnloadOption = NXOpen.Session.LibraryUnloadOption.AtTermination

End Function

End Module[/vbnet]

Using the Point3d version of the method is super easy, simply pass in two Point3d variables to the CreateLine method representing the start point and end point of the line - and that's it, you are done.

Using the CreateLine method that takes two Point objects is only slightly more complicated; after you create the line you will need to make it visible and remove the parameters. If you do not remove the parameters, the resulting line will remain associative to the two point objects (comment out the line of code that removes the parameters to try it out, move one or both points and the line will follow). An associative line doesn't sound so bad until you realize there is no way to edit the associativities in interactive NX, nor does it show up in the feature tree as an associative line feature would. We'll look at creating associative line features in an upcoming tutorial.

Finally, here is some code that uses the CreateLine method and a recursive subroutine to create some interesting fractal trees.

[vbnet]
'NXJournaling
'a journal that creates fractal trees using the CreateLine method and recursion

Option Strict Off
Imports System
Imports System.Math
Imports NXOpen

Module Module1

Dim theSession As Session = Session.GetSession()
Dim workPart As Part = theSession.Parts.Work
Dim deg_to_rad As Double = Math.PI / 180

Sub Main()

Dim markId1 As Session.UndoMarkId
markId1 = theSession.SetUndoMark(Session.MarkVisibility.Visible, "NXJournaling.com")

Dim depth As Integer = 9
Dim ptStart As Point3d = New Point3d(0, 0, 0)
DrawTree(ptStart, 90, depth)

End Sub

Sub DrawTree(ByVal startPoint As Point3d, ByVal angle As Double, ByVal depth As Integer)

If depth = 0 Then
Exit Sub
End If

Dim ptEnd As Point3d
ptEnd.X = startPoint.X + Math.Cos(deg_to_rad * angle) * depth * 10
ptEnd.Y = startPoint.Y + Math.Sin(deg_to_rad * angle) * depth * 10
ptEnd.Z = 0
workPart.Curves.CreateLine(startPoint, ptEnd)
DrawTree(ptEnd, angle - 20, depth - 1)
DrawTree(ptEnd, angle + 20, depth - 1)

End Sub

Public Function GetUnloadOption(ByVal dummy As String) As Integer

'Unloads the image when the NX session terminates
GetUnloadOption = NXOpen.Session.LibraryUnloadOption.AtTermination

End Function

End Module
[/vbnet]