1. Select the item unit you wish to display with open door(s).
2. Select the 'Items' tab from within the ribbon.
3. Click on the Properties button.
4. Within the 'Unit Properties' pane, click on the navigation arrows to find the 'Door Open' function.
5. Input the numerical value of how far open the door must be. This is based on your standard unit of measurement. A preview will appear on the right-hand side if the 'Perspective' radio button is selected.
6. Click on OK to confirm the changes or Cancel to ignore them.
7. If OK was clicked, the selected item will now have an open door.