By default, Instant Terra displays in the Viewport the terrain or mask generated by the currently selected node. It is sometimes useful to make changes to a node or the graph while viewing the effects on another node. To do this, you can freeze the display so that the terrain or mask currently displayed remains visible in the Viewport regardless of the selected node.
If no node is selected, if multiple nodes are selected, or if the selected node generates something other than a terrain or a mask, nothing is displayed in the Viewport.
To freeze the display, either:
- Press the Space key.
- Click the Lock display icon
. - Select View > Lock display in the menu.
When the display is frozen, the Lock display
icon changes to a closed, red padlock. 
The appearance of the selected node changes.
Even when the display is frozen, you can still move the camera in the Viewport.
To unfreeze the display, either:
- Press the Space key.
- Click the red Unlock display icon .
- Select View > Unlock display in the menu.