Godot 3.1.1
Based off of Godot's TileMap Node.
See Demo folder for example.
Instance a scene from Zones/WorldInstanceBaseScene
All occupied cells I.E. terrain that actors cannot walk on is drawn using the tilemap "InteractiveTerrain."
All non-occupied cells I.E. background tiles are drawn using the tilemap "Non-InteractiveTerrain"
The final tilemap AlwaysOnTop is for non-occupied forground tiles that should always be drawn over objects (roofs, treetops, etc.)
All overworld objects, actors, etc. are children of InteractiveTerrain in this example.