You can set the CityEngine preferences by clicking Edit > Preferences in the main menu.
You can set Viewport preferences under General > Viewport.
The following are the Viewport preferences :
You can change the appearance and behavior of 3D viewports.
Color options  | Set various colors for scene elements.  | 
| Animation time [ms] | Set time for camera animations (for example, when triggering a camera bookmark).  | 
| Disable camera during camera navigation | Speed up camera navigation on heavier scenes.  | 
| Line width | Set width for line rendering.  |