Create and manipulate a reference plane and Underlay an image
Use the Define and Edit reference plane tools to quickly create and manipulate a reference plane in your 3D environment. You can also load Underlay images on your reference planes.
Select Define Reference Plane tool and click any face of an object to define a new reference plane.
Select Edit Reference Plane tool then drag controls to move, rotate, and re-size your reference plane.
Invoke the Reference Plane Parameters palette from the Palettes pull-down menu, then turn ON the Underlay option, then click the Load button to load your underlay image.
In the Reference Plane Parameters palette set underlay size, scale, and transparency as desired.
Note, you can still move and rotate your reference plane, with the underlay, using the Edit Reference Plane tool. Also, different underlay images can be loaded on different reference planes.