In the Unity editor:
- Edit -> Project Settings -> Editor
- In the inspector panel, set:
- Version Control -> Mode: Visible Meta Files
- Asset Serialization -> Mode: Force Text
“Visible Meta Files” causes Unity to place .meta files next to each of your assets. It’s important to check these files into version control because they contain the settings associated with those assets that you set in the Unity editor.
“Asset Serialization: Force Text” causes Unity to write its .meta and other files in a more-or-less human-readable text format, which makes it a lot easier to understand what has changed when you look at version control logs. Also it’s feasible to merge these text files by hand, whereas it’s not really possible to do that with Unity’s default binary file format.