is3D(): Boolean;
The is3D method of the Control class returns whether the control was drawn three-dimensionally (that is, it returns true if the show3D property was set to Show3D_Use3D or to Show3D_UseAppDefault and that control was selected in the 3D Controls list box of the Form sheet of the Define Application dialog).
This method returns false if the show3D property was set to Show3D_Not3D or the control was not selected with the three-dimensional default value for the application.
You can call this method only on a control that has an associated window.