Terrain type is capitalized

src/engine/objects/Zone.java

@@ -110,7 +110,7 @@ public class Zone extends AbstractGameObject {
             this.terrain_type = "PLANAR";
         }
 
-        if (this.terrain_type.equals("None"))
+        if (this.terrain_type.equals("NONE"))
             this.terrain = null;
         else
             this.terrain = new Terrain(this);