Is there any way to change the sun direction on a map in the editor? Change the cardinal directions so to speak? I know I can turn the terrain but when there are already plenty of objects placed it is not really possible to turn it without ruining most of the work that has been done before...
You can find TimeOfDay of the map and edit azimuthOverride and axisTilt to change the sun direction. Speaking of this, I remember when I have the same issue and was searching for information about rotating the terrian on the forum, I found that it seems you cannot rotate the terrain for an alternative solution, because the collision of the terrain won't rotate along with the terrain. So if you really want to do this, you may need to export the terrain, rotate the heightmap and texture map, and re-import the terrain.
Yes I found out both eventually. Its weird that it is possible to change all parameters of the terrain, except the rotation. And the game apparently turns a heightmap by 90 degrees when importing it since my original heightmap was north oriented correctly but showed up wrong in Beam Ng. Anyways, changing the sun was the easier solution..