Customize menu > Preferences > Preferences Settings dialog > GCS panel
On the GCS panel of the Preferences dialog, you can set and define Global Coordinate Systems.
If you're working with data that uses a variety of projections and origins, choose a global coordinate system to be used as a standard for all maps and project scenes. Use the following options to set the default project scene global coordinate system. You should only change this default after thorough consideration and the change should apply to all scenes in the same project.
Use Coordinate System—Allows you to use a coordinate system defined in the Select Global Coordinate System dialog When you turn this option on, the Change and Define buttons become available. When you turn off this option, Autodesk VIZ ignores any global coordinate system in your data.
Change—Displays the Select Global Coordinate System dialog, where you can change the coordinate system applied to your scene.
Define—Displays the Global Coordinate System Manager dialog, where you can create, edit, or delete a coordinate system.
Do Geometry Transformation—If you use data that was created using a different global coordinate system, Autodesk VIZ standardizes the data based on the current scene's global coordinate system code (as set in the above options). When you turn this option on, Autodesk VIZ performs a transformation on the geometry to adjust it to the current scene's global coordinate system.