using TSG = Tekla.Structures.Geometry3d;

using TSMU = Tekla.Structures.Model.UI;

Model myModel = new Model();

TSMU.ModelObjectSelector modelObjectSelector = new TSMU.ModelObjectSelector();
            TSMU.Picker picker = new TSMU.Picker();
            TSG.Point p1 = picker.PickPoint();
            TSG.Point p2 = picker.PickPoint();
            Vector v = new Vector(p2.X - p1.X, p2.Y - p1.Y, p2.Z - p1.Z);

            foreach (TSM.ModelObject item in modelObjectSelector.GetSelectedObjects())
            {
                Operation.MoveObject(item, v);
            }
            myModel.CommitChanges();
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