Use half extents as offset from center

src/engine/InterestManagement/Terrain.java

@@ -184,8 +184,8 @@ public class Terrain {
 
         // Normalize terrain offset
 
-        Vector2f normalizedOffset = new Vector2f(Math.abs(zone_offset.x) / this.terrain_size.x,
-                Math.abs(zone_offset.y) / terrain_size.y);
+        Vector2f normalizedOffset = new Vector2f(Math.abs(zone_offset.x) / this.zone.major_radius,
+                Math.abs(zone_offset.y) / this.zone.minor_radius);
 
         float xval;
 

src/engine/devcmd/cmds/GetHeightCmd.java

@@ -40,8 +40,8 @@ public class GetHeightCmd extends AbstractDevCmd {
 
         Vector2f zoneLoc = ZoneManager.worldToTerrainSpace(playerCharacter.getLoc(), heightmapZone);
         Vector2f zoneOffset = ZoneManager.worldToZoneOffset(playerCharacter.getLoc(), heightmapZone);
-        Vector2f normalizedOffset = new Vector2f(Math.abs(zoneOffset.x) / heightmapZone.terrain.terrain_size.x,
-                Math.abs(zoneOffset.y) / heightmapZone.terrain.terrain_size.y);
+        Vector2f normalizedOffset = new Vector2f(Math.abs(zoneOffset.x) / heightmapZone.major_radius,
+                Math.abs(zoneOffset.y) / heightmapZone.minor_radius);
 
         Vector2f gridSquare = heightmapZone.terrain.getTerrainCell(zoneLoc);
         gridSquare.x = (float) Math.floor(gridSquare.x);