diff --git a/utils/line_sphere_intersection.py b/utils/line_sphere_intersection.py
deleted file mode 100644
index 2b7fe17..0000000
--- a/utils/line_sphere_intersection.py
+++ /dev/null
@@ -1,103 +0,0 @@
-import math
-import numpy as np
-
-def isBetween(x, a, b):
-    #check if x is between the segment composed by point a and point b
-    if (a <= x <= b or a >= x >= b):
-        return True
-    else:
-        return False
-    
-
-def line_sphere_intersection(point_A, point_B, sphere_center, radius):
-    # line has two points(pointA and pointB)
-    # sphere_center(x, y, z)
-    # radius is the sphere's radius
-    a = (point_B[0] - point_A[0])**2 + (point_B[1] - point_A[1])**2 + (point_B[2] - point_A[2])**2
-
-    b = 2* ((point_B[0] - point_A[0])*(point_A[0] - sphere_center[0]) + 
-            (point_B[1] - point_A[1])*(point_A[1] - sphere_center[1]) + 
-            (point_B[2] - point_A[2])*(point_A[2] - sphere_center[2]))
-    c = (point_A[0] - sphere_center[0])**2 + (point_A[1] - sphere_center[1])**2 + (point_A[2] - sphere_center[2])**2 - radius**2
-
-    delta = b**2 - (4*a*c)
-
-    d1 = (-b+np.sqrt(delta))/(2*a)
-    d2 = (-b-np.sqrt(delta))/(2*a)
-    
-    if (delta < 0) :
-        print("delta < 0")
-        return None
-    elif (delta > 0):
-        print("delta > 0")
-        # one point
-        x1 = point_A[0] + d1*(point_B[0] - point_A[0])
-        y1 = point_A[1] + d1*(point_B[1] - point_A[1])
-        z1 = point_A[2] + d1*(point_B[2] - point_A[2])
-        # the other one
-        x2 = point_A[0] + d2*(point_B[0] - point_A[0])
-        y2 = point_A[1] + d2*(point_B[1] - point_A[1])
-        z2 = point_A[2] + d2*(point_B[2] - point_A[2])
-
-        result = []
-        if isBetween((x1, y1, z1), point_A, point_B):
-            result.append((x1, y1, z1))
-        if isBetween((x2, y2, z2), point_A, point_B):
-            result.append((x2, y2, z2))
-        if len(result) == 0:
-            return None
-        else:
-            return result
-    else:
-        print("delta = 0")
-        d1 = -b / (2*a)
-        # one point
-        x1 = point_A[0] + d1*(point_B[0] - point_A[0])
-        y1 = point_A[1] + d1*(point_B[1] - point_A[1])
-        z1 = point_A[2] + d1*(point_B[2] - point_A[2])
-        if isBetween((x1, y1, z1), point_A, point_B):
-            return (x1, y1, z1)
-        else:
-            return None
-
-# one point intersection (work)
-# sphere = (0, 0, 0)
-# redius = 1
-# point_A = (1, 1, 0)
-# point_B = (1, -1, 0)
-# result = line_sphere_intersection(point_A, point_B, sphere, redius)
-# print(result)
-
-# two point intersection (work)
-# sphere = (0, 0, 0)
-# redius = 1
-# point_A = (1, 0, 0)
-# point_B = (-1, 0, 0)
-# result = line_sphere_intersection(point_A, point_B, sphere, redius)
-# print(result)
-
-# no intersection (work)
-# sphere = (0, 0, 0)
-# redius = 1
-# point_A = (2, 0, 0)
-# point_B = (2, 2, 0)
-# result = line_sphere_intersection(point_A, point_B, sphere, redius)
-# print(result)
-
-# no intersection (work)
-# suppose to be one, but it is not in the segment 
-# sphere = (0, 0, 0)
-# redius = 1
-# point_A = (2, 0, 0)
-# point_B = (3, 0, 0)
-# result = line_sphere_intersection(point_A, point_B, sphere, redius)
-# print(result)
-
-# one point intersection (work)
-# suppose to be two, but one is not in the segment
-# sphere = (0, 0, 0)
-# redius = 1
-# point_A = (0, 0, 0)
-# point_B = (3, 0, 0)
-# result = line_sphere_intersection(point_A, point_B, sphere, redius)
-# print(result)
\ No newline at end of file