unity3d - Share same Navmesh with Duplicated Scenes -

i had scene map (some buildings , roads) , baked navmesh, started duplicating same scene modifying objects inside (not map or world), scenes sharing same navmesh somehow, deleted navmesh accidentally, way seem find create new baked navmesh every scene increase build size much!, how can re-share same baked navmesh scenes since have same map inside ? using latest unity3d.

before start: if have lot of assets in project changing serialization force text may take lot of time. may want copy target scenes new project, below mentioned steps , paste them back. :)

there no way unity editor, there workaround:

1. go edit > project settings > editor , change asset serialization force text (default mixed) - makes sure assets, including unity scene files saved text documents
2. now open scene file (the 1 baked navmesh) in text editor
3. cmd+f or ctrl+f focus on search bar , type "navmeshsettings". in navmeshsettings last entree should m_navmeshdata:{fileid:1234 //and more stuff here} - reference baked navmesh asset file. copy whole line
4. now open second scene want share navmesh (open in text editor again). find same line starting m_navmeshdata, delete , past line previous scene.
5. boom!

edit/tip: may want change serialization mixed again if want to. downside of texted serialization bigger files. used version controlling , merging , scenes , stuff...