完整的进行Unity 3D源码用Git管理的流程：

1 新建文件夹(路径要求非空)

2 新建U3D项目

3 添加.gitignore文件

获取已有的U3D项目

修改Unity 3D编辑器：

Enable External option in Unity → Preferences → Packages → Repository. (Skip this step in v4.5 and up)

Switch to Visible Meta Files in Edit → Project Settings → Editor → Version Control Mode.

Switch to Force Text in Edit → Project Settings → Editor → Asset Serialization Mode.

Save the scene and project from File menu.

.gitignore：

# =============== #

# Unity generated #

# =============== #

Temp/

Library/

# ===================================== #

# Visual Studio / MonoDevelop generated #

# ===================================== #

ExportedObj/

obj/

*.svd

*.userprefs

/*.csproj

*.pidb

*.suo

/*.sln

*.user

*.unityproj

*.booproj

# ============ #

# OS generated #

# ============ #

.DS_Store

.DS_Store?

._*

.Spotlight-V100

.Trashes

ehthumbs.db

Thumbs.db