parameter ordering fixed.

src/engine/InterestManagement/HeightMap.java

@@ -260,7 +260,7 @@ public class HeightMap {
 
             float areaDelta = childArea / parentArea;
 
-            interpolatedTerrainHeight = FastMath.LERP(interpolatedTerrainHeight, parentHeight, areaDelta);
+            interpolatedTerrainHeight = FastMath.LERP(areaDelta, interpolatedTerrainHeight, parentHeight);
             return interpolatedTerrainHeight + heightMapZone.worldAltitude;
 
         }