Point light not rendering all angles of its sphere on terrain?

I'm having a very strange issue where Point Lights are not rendering about 40% of it's radius. Here are some screenshots showing the problem...



You can see the radius sphere here and how it's only shining light on one side of it.




You can see again that it is acting as if something is blocking it.



This is the same exact light in the same location as the 1st screenshot, except viewed in game. You can clearly see where the circle gets cut off.



I've tested other lights, from different sources (such as attatching a light to projectiles), and it seems no matter what angle I shoot it from, the world vector direction of (1,0,1) gets cut off (you can see what I mean in the 1st screenshot with the X/Y/Z indicator in the top right). When I shot projectiles from every angle, that side always had the light cut off. It's not local to the light, so it's something related to either world coordinates or the terrain.

Any idea what could be causing this? It's very frustrating as it's ruining the look of my scene...

 

I have the same problem, have no idea why that's happening. bumping the thread