Studio checks the map after every edit, the same way Install does, so you find out about a broken portal when you make it, not when you install.
Problems
The Problems panel on the rail, and the Problems and changes dock under the map, list what would stop an install and what it would warn about. The rail icon and the dock's title carry the count. Click a row to select the object it is about and fly to it.
Click the dock's title to open or fold it. It stays the way you leave it.
Changes
The Changes view, beside Problems, lists:
- the files Install would write, each marked client or server;
- every object added, changed or deleted since the map was opened, folded across the undo history, so moving a crate there and back again shows as no change.
The preview
Changes to things the client draws, such as props and map settings, are rebuilt into the map a moment after you make them, exactly as Install would write them. The status bar shows Updating the preview while that happens. The map you are looking at stays on screen until the new one is ready.
Undo and redo
Ctrl + Z undoes and Ctrl + Y (or Ctrl + Shift + Z) redoes, as far back as the map was opened. The undo and redo buttons in the toolbar, and the Edit menu, name the step they will undo or redo. The History list on the Tools panel jumps several steps at once.
Every drag, stroke, paste and arrangement is one step. Esc during a drag puts everything back without adding a step.