Topic: Matrix3d Help.

[WOWENS]

I'm trying to Align the Z Axis with 2 points, that works but I'm 90deg off around the Z Axis any help would be appreciated

Shared Function UCSAlignZaxix(ByVal Point1 As Point3d, ByVal Point2 As Point3d) As Matrix3d

        Try
            Dim ZAxis As Vector3d = Point1.GetVectorTo(Point2).GetNormal
            Dim yAxis As Vector3d = ZAxis.GetPerpendicularVector.GetNormal
            Dim xAxis As Vector3d = yAxis.CrossProduct(ZAxis).GetNormal

            Dim NewMatrix3d As Matrix3d = Matrix3d.AlignCoordinateSystem(Point3d.Origin, Vector3d.XAxis, Vector3d.YAxis, Vector3d.ZAxis, Point1, xAxis, yAxis, ZAxis)

            Return NewMatrix3d
        Catch
            Return Nothing
        End Try
    End Function

[zoltan]

Would it work better if you determined the X axis first and then arrived at the Y axis from the cross product?

Take a look at this:

http://www.autodesk.com/techpubs/autocad/acadr14/dxf/arbitrary_axis_algorithm_al_u05_c.htm

[WOWENS]

that took care of it, thanks

Dim XAxis As Vector3d = ZAxis.GetPerpendicularVector.GetNormal
Dim YAxis As Vector3d = ZAxis.CrossProduct(XAxis).GetNormal