When you are running ZW3D it is referred to as the Active Session. When you create a new file it resides in the active session and contains the initial root objects that you create. When you save a file that is new and has not been saved yet, the File Browser is displayed and defaults to the "File Save" directory defined on the Files tab of the ZW3D Configuration Form or the last directory specified by this command or the Save File As command. If you save all files and one of the files is new, it is saved from the active session to the "File Save" directory mentioned above.

When you open a file, the active session only retrieves the root objects and sub-objects needed. Also, display information is loaded on-demand. Display information that lies outside the initial view window, that is blanked, or that isn't needed for the active display mode (e.g., facets for shading) is not loaded. This is all part of ZW3D's efficient object manager.

Tips & Techniques

It is important to remember that the undo and redo history is maintained only during each session and that every time a file in the session is saved, the undo/redo history is reset.