Version: 5.4 (switch to 5.3)
2D and 3D Mode Settings
Build Settings

Preferences

Unity provides a number of preference panels to allow you to customise the behaviour of the editor.

General

Auto Refresh Should the editor update assets automatically as they change?
Load Previous Project on Startup Should the previous project be shown at startup?
Compress Assets On Import Should assets be compressed automatically during import?
OSX Color Picker Mac OSX Only: Should the native OSX color picker be used instead of Unity’s own?
Disable Editor Analytics Can the editor send information back to Unity automatically?
Show Asset Store search hits Should the number of free/paid assets from the store be shown in the Project Browser?
Verify Saving Assets Should Unity verify which assets to save individually on quitting?
Editor Skin Which color scheme should Unity use for the editor? Professional users have the option of dark grey in addition to the default light grey Personal skin.
Enable Alpha Numeric Sorting This option enables a new button in the top right corner of the Hierarchy window, allowing you to switch between Transform sort (which is the default behaviour) and Alphanumeric sort.

External Tools

Setting Properties
External Script Editor Select which application Unity should use to open script files. Unity automatically passes the correct arguments to script editors it has built-in support for. Unity has built-in support for MonoDevelop, Xamarin Studio, Visual Studio (Express) and Visual Studio Code.
External Script Editor Args Select which arguments to pass to the external script editor.
$(File) is replaced with a path to a file being opened.
$(Line) is replaced with a line number that editor should jump to.
$(ProjectPath) is replaced with the path to the open project.
If not set on macOS, then the default mechanism for opening files is used. Otherwise, the external script editor will only be launched with the arguments without trying to open the script file using the default mechanism.
Add .unityproj’s to .sln Check this box to add UnityScript (.unityproj) and Boo (.booproj) projects to the generated solution (.sln) file. This is enabled by default for MonoDevelop and Xamarin Studio, and disabled by default for Visual Studio (Express) and Visual Studio Code.
Editor Attaching Check this box to allow debugging of scripts in the Unity Editor. If this option is disabled, it is not possible to attach a script debugger to Unity to debug your scripts.
Image Application Choose which application you want Unity to use to open image files?
Revision Control Diff/Merge Choose which application you want Unity to use to resolve file differences with the Asset server.

Colors

This panel allows you to choose the colors that Unity uses when displaying various user interface elements.

Keys

This panel allows you to set the keystrokes that activate the various commands in Unity.

GI Cache

Maximum Cache Size (Gb) The GI cache folder will be kept below this size whenever possible. A background job will periodically clear out unused files.
Custom Cache Location Allows a custom location for the GI cache. The cache folder will be shared between all projects.
Cache compression This enables a fast real time compression of the GI Cache files to reduce the size of the generated data. If you need to access the raw Enlighten data you should disable Cache Compression and clean the cache.
Clean Cache Use this button to clean the cache.
Cache Size Current Cache size.
Cache Location Current Cache location.

2D

Maximum Sprite Atlas Cache Size (GB)

Cache Server

Use Cache Server Should the cache server be enabled?
IP Address IP address of the cache server, if enabled
2D and 3D Mode Settings
Build Settings