Create Line from Intersecting Point

[priyanka_mehta]

Hi all,

 

I have three polylines. Two of these intersect and make something like an X. My third polyline does not intersect with these two. Now, I want to create a perpendicular line start point being the intersection point of these two lines.

 

Any help would be appreciated.

 

Thanks and Regards,

Priyanka

[lpseifert]

............

Command: line

Specify first point: int

of (select intersection)

Specify next point or [undo]: per

to (select third line)

[Lee Mac]

I'm assuming you mean perpendicular to the third line that does not intersect the other two - like attached?

[Lee Mac]

Do you really need a LISP to accomplish this - is it not just easier to draw the line yourself, as I have done in the example?

 

lpseifert has shown you how in his above post...

[priyanka_mehta]

Yes i do need a code for it because i have hundereds of such points.. and actually i would need a VBA code for this...

 

 

and one more thing...

i wanted the coordinates where the lines intersect.. The code i was using is below.. The code was working perfectly well when all of a sudden i started getting this error

 

" Runtime-error '-2145320923(8021001c)

AutoCAD main window is invisible" .. How do i get rid of this error!

 

I am just 2 days old to AutoCAD VBA and i have no idea what does this error mean

 

 

Please Help!!

 

 

The code i am using is:

// Get INTERSECTION POINTS

 

Sub GetIntersectionPoints()

Dim SOS As AcadSelectionSet

Dim objSS As AcadSelectionSet

For Each SOS In ThisDrawing.SelectionSets

If SOS.Name = "MySS" Then

ThisDrawing.SelectionSets("MySS").Delete

Exit For

End If

Next

ThisDrawing.SelectionSets.Add ("MySS")

Set objSS = ThisDrawing.SelectionSets("MySS")

objSS.SelectOnScreen

'Filter Lines and polylines only

Dim ArrayToRemove() As AcadEntity

Dim objEnt As AcadEntity

Dim Num As Integer

Num = -1

For Each objEnt In objSS

If objEnt.ObjectName "AcDbLine" And objEnt.ObjectName "AcDbPolyline" Then

Num = Num + 1

If Num = 0 Then

ReDim ArrayToRemove(0)

Else

ReDim Preserve ArrayToRemove(Num)

End If

Set ArrayToRemove(Num) = objEnt

End If

Next

objSS.RemoveItems ArrayToRemove

If objSS.Count > 0 Then

Else

MsgBox "No lines and polylines selected!"

Exit Sub

End If

Dim ArrayWithCoordinates() As Double

Num = -1

Dim i As Integer

Dim j As Integer

Dim k As Integer

Dim Pts As Variant

For i = 0 To objSS.Count - 2

For j = i + 1 To objSS.Count - 1

Pts = objSS(i).IntersectWith(objSS(j), acExtendNone)

If UBound(Pts) > -1 Then

For k = 0 To UBound(Pts)

Num = Num + 1

If Num = 0 Then

ReDim ArrayWithCoordinates(0)

Else

ReDim Preserve ArrayWithCoordinates(Num)

End If

ArrayWithCoordinates(Num) = Pts(k)

Next

End If

Next

Next

'get the lines and polylines selected for beter user visualisation

For i = 0 To objSS.Count - 1

objSS(i).Highlight True

Next

 

'Display coordinates of all intersection points

Dim MessageArray As String

MessageArray = ""

If Num > -1 Then

For i = 0 To UBound(ArrayWithCoordinates) - 2 Step 3

MessageArray = MessageArray & ArrayWithCoordinates(i) & _

", " & ArrayWithCoordinates(i + 1) & ", " & ArrayWithCoordinates(i + 2) & vbCr

Next

MsgBox MessageArray, , "Coordinates of intersection points"

Else

MsgBox "No intersection points found"

End If

End Sub

 

 

 

Thanks and Regards,

Priyanka

[priyanka_mehta]

Hi again..

I have found the solution to get rid of that idotic runtime error.. i just had to make that form non-modal

 

Anyways still i want a VBA code for creating perpendicular line from intersection point.

 

Thanks and Regards,

Priyanka