[abenedik]

Why do you think that you "first i need to move, then rotate and at last scale"?

Of you want to have stretched and rotated object, then you will need to first scale it and then rotate it - this is the order that needs to be in the Transform3DGroup - for example:

Code:

var transform3DGroup = new Transform3DGroup();
transform3DGroup.Children.Add(new ScaleTransform3D(2, 1, 1)); // scale x for 2x
transform3DGroup.Children.Add(new RotateTransform3D(new AxisAngleRotation3D(new Vector3D(0,1,0), 45))); // rotate by 45 degrees around Y axis