This is something I put together for a University project based on ActionStreetMap, a very cool Unity framework for building maps from OpenStreetMap data.
The ActionStreetMap demo builds up the world as you move around it, but for this project I wanted to pre-generate the world so that at runtime nothing gets generated. Therefore, I created this project based on the ASM demo code, to generate the entirety of a map area (specified via properties in the Unity editor) and then export all the data as prefabs. This can be packaged up and imported into another project.
Note that the implementation is fairly hacky as the project has a short time scale, but it works and might be useful to someone else.
All credit should go to the ActionStreetMap author(s), I've just reworked their demo to do this!
Open up the Main scene, select the Main Camera object and enter the required parameters on the Map Gen Manager component. Press play and wait until the "Map generation complete" message appears. You should now see a Map prefab in Assets/Generated. Note that each time the game is run, the existing Generated folder will be deleted.
This prefab can be exported as a package to be imported into another project. Note that when selecting the assets to export in the package, you should deselect all plugins, and all scripts other than MapProperties.cs. This script is added to the generated map parent object to include the properties it was generated with. Unity does not detect that only that script is required and tries to pull all scripts/plugins into the package.