diff --git a/spheroid.cpp b/spheroid.cpp
index d55f451..b6cb9f6 100644
--- a/spheroid.cpp
+++ b/spheroid.cpp
@@ -68,7 +68,7 @@ void Spheroid::check_perlin_collision(PerlinNoise perlin) {
 
 
 double Spheroid::operator() (double _x, double _y, double _z) const {
-            return (pow(_x - center.x, 2) / pow(q, 2)
-                  + pow(_y - center.y, 2) / pow(q, 2)
-                  + pow(_z - center.z, 2) / pow(p, 2) -1);
+            return (pow(_x, 2) / pow(q, 2)
+                  + pow(_y, 2) / pow(q, 2)
+                  + pow(_z, 2) / pow(p, 2) -1);
 }