I want to auto rotate the view viewing
I add a code to change CameraPosition in a timer but it did not work

Private Sub Timer1_Tick(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Timer1.Tick
       ' dgView3D.CameraRotation = New Point3D(dgView3D.CameraRotation.X, dgView3D.CameraRotation.Y + 5, dgView3D.CameraRotation.Z)
       With dgView3D.CameraPosition
           Dim angleInPie As Double = _CurrentAngle * (Math.PI / 180)
           Dim sinOfAngle As Double = Math.Sin(angleInPie)
           Dim cosOfAngle As Double = Math.Cos(angleInPie)

           Dim nextX As Single = .X * cosOfAngle - .Y * sinOfAngle
           Dim nextY As Single = .Y * sinOfAngle + .Y * cosOfAngle
           Dim nextZ As Single = .Z

           dgView3D.CameraPosition = New Point3D(nextX, nextY, nextZ)
           _CurrentAngle += 1
           If _CurrentAngle > 360 Then

               _CurrentAngle = 0
           End If
           dgView3D.ResetProjection()
       End With

    End Sub

I can't make any sense of your X and Y assignments. If you need the camera to move in a circle around some point in a fixed Z plane, use this formula:

nextX = point.X + radius * Math.Cos(angle);
nextY = point.Y + radius * Math.Sin(angle);

Then you can call the PointCameraTo method to point the camera to the center point.

I hope that helps,
Stoyan

It should be the distance from the camera to the rotation center, assuming you want the camera to move around that point. If you need the camera to stay in the same location but just change its orientation, you should only increment the CameraRotation angles.

I hope that helps,
Stoyan