WCS UCS Point Transformations

[SRSDS]

I am using the following to transform coordinates

    Public Function TransformPointWCStoUCS(ByVal WCSPnt As Point3d) As Point3d
        Dim ed As Editor = Application.DocumentManager.MdiActiveDocument.Editor
        Dim m As Matrix3d = ed.CurrentUserCoordinateSystem.Inverse()
        Return WCSPnt.TransformBy(m)
    End Function

    Public Function TransformPointUCStoWCS(ByVal UCSPnt As Point3d) As Point3d
        Dim ed As Editor = Application.DocumentManager.MdiActiveDocument.Editor
        Dim m As Matrix3d = ed.CurrentUserCoordinateSystem
        Return UCSPnt.TransformBy(m)
    End Function

The WCS to UCS is returning a negative value for Y. Is there another version of these that I need to be using?

[AubelecBE]

here my code for one function :

  '-------------------------------------------------------------------------
    '------ Conversion d'un point vers le WCS (SCU général)-------------------
    '-------------------------------------------------------------------------
    'Entrée : 
    '   un point 3D
    '   Debug : si true alors affichage
    '
    'Sortie : Un point 3D
    '-------------------------------------------------------------------------

    Public Function TransformPointToWCS(ByRef point As Point3d, Optional ByVal Debug As Boolean = False) As Point3d
        Dim doc As Document = Autodesk.AutoCAD.ApplicationServices.Application.DocumentManager.MdiActiveDocument
        Dim ed As Editor = doc.Editor
        Dim Db As Database = doc.Database
        Dim ret As Point3d

      
        'conversion vers le WCS (du point uniquement)
        Dim newMatrix As Matrix3d '= New Matrix3d()
        Dim ucs As Matrix3d = ed.CurrentUserCoordinateSystem
        Dim cs As CoordinateSystem3d = ucs.CoordinateSystem3d
        newMatrix = Matrix3d.AlignCoordinateSystem(
            Point3d.Origin, _
            Vector3d.XAxis, _
            Vector3d.YAxis, _
            Vector3d.ZAxis, _
            cs.Origin, _
            cs.Xaxis, _
            cs.Yaxis, _
            cs.Zaxis)

     
        ret = point.TransformBy(newMatrix)
        If Debug = True Then
            ed.writemessage(vbCrLf & "x : avant " & point.X & " apres : " & ret.X & _
                                     vbCrLf & "y : avant " & point.Y & " apres : " & ret.Y)
        End If
        Return ret
     
    End Function

[_gile]

Hi,

You can have a look at the Point3d.Trans() overloaded extension methods in the GemetryExtensions library and/or at a way to P/Invoke the acedTrans() ObjectARX method.