test: add rod-sphere contact tests for collision scenarios

Author: skim0119

tests/test_contact_classes.py

@@ -547,6 +547,92 @@ def test_contact_rod_sphere_with_collision_with_k_without_nu_and_friction(
             atol=1e-6,
         )
 
+    def test_contact_rod_sphere_without_collision(
+        self,
+    ):
+        "Testing Rod Sphere Contact wrapper without Collision"
+
+        mock_rod = MockRod()
+        mock_sphere = MockSphere()
+        rod_sphere_contact = RodSphereContact(k=1.0, nu=0.0)
+
+        # Setting sphere position such that there is no collision
+        mock_sphere.position_collection = np.array([[100], [200], [300]])
+
+        mock_rod_external_forces_before_execution = mock_rod.external_forces.copy()
+        mock_sphere_external_forces_before_execution = (
+            mock_sphere.external_forces.copy()
+        )
+        mock_sphere_external_torques_before_execution = (
+            mock_sphere.external_torques.copy()
+        )
+
+        rod_sphere_contact.apply_contact(mock_rod, mock_sphere)
+
+        assert_allclose(
+            mock_rod.external_forces, mock_rod_external_forces_before_execution
+        )
+        assert_allclose(
+            mock_sphere.external_forces,
+            mock_sphere_external_forces_before_execution,
+        )
+        assert_allclose(
+            mock_sphere.external_torques,
+            mock_sphere_external_torques_before_execution,
+        )
+
+    def test_contact_rod_sphere_with_collision_with_nu_without_k(
+        self,
+    ):
+        "Testing Rod Sphere Contact wrapper with Collision with nu without k"
+
+        mock_rod = MockRod()
+        mock_rod.velocity_collection = np.array([[-1, 0, 0], [-1, 0, 0], [-1, 0, 0]])
+
+        mock_sphere = MockSphere()
+        mock_sphere.velocity_collection = np.array([[1], [0], [0]])
+
+        rod_sphere_contact = RodSphereContact(k=0.0, nu=1.0)
+        rod_sphere_contact.apply_contact(mock_rod, mock_sphere)
+
+        assert_allclose(
+            mock_sphere.external_forces, np.array([[-1.5], [0], [0]]), atol=1e-6
+        )
+        assert_allclose(
+            mock_sphere.external_torques, np.array([[0], [0], [0]]), atol=1e-6
+        )
+        assert_allclose(
+            mock_rod.external_forces,
+            np.array([[0.5, 1.0, 0], [0, 0, 0], [0, 0, 0]]),
+            atol=1e-6,
+        )
+
+    def test_contact_rod_sphere_with_collision_with_k_and_nu(
+        self,
+    ):
+        "Testing Rod Sphere Contact wrapper with Collision with k and nu"
+
+        mock_rod = MockRod()
+        mock_rod.velocity_collection = np.array([[-1, 0, 0], [-1, 0, 0], [-1, 0, 0]])
+
+        mock_sphere = MockSphere()
+        mock_sphere.velocity_collection = np.array([[1], [0], [0]])
+
+        rod_sphere_contact = RodSphereContact(k=1.0, nu=1.0)
+        rod_sphere_contact.apply_contact(mock_rod, mock_sphere)
+
+        assert_allclose(
+            mock_sphere.external_forces, np.array([[-2.0], [0], [0]]), atol=1e-6
+        )
+        assert_allclose(
+            mock_sphere.external_torques, np.array([[0], [0], [0]]), atol=1e-6
+        )
+        assert_allclose(
+            mock_rod.external_forces,
+            np.array([[0.666666, 1.333333, 0], [0, 0, 0], [0, 0, 0]]),
+            atol=1e-6,
+        )
+
 
 class TestRodPlaneContact:
     def initializer(

tests/test_contact_functions.py

@@ -624,7 +624,7 @@ def test_calculate_contact_forces_rod_sphere_with_k_without_nu_and_friction(
 
         "initializing sphere parameters"
         sphere = MockSphere()
-        x_sph = sphere.position[..., 0] - sphere.radius * sphere.director[2, :, 0]
+        x_sph = sphere.position[..., 0]
 
         "initializing constants"
         """
@@ -640,16 +640,11 @@ def test_calculate_contact_forces_rod_sphere_with_k_without_nu_and_friction(
         _calculate_contact_forces_rod_sphere(
             rod_element_position,
             rod.lengths * rod.tangents,
-            sphere.position[..., 0],
             x_sph,
-            sphere.radius * sphere.director[2, :, 0],
             rod.radius + sphere.radius,
             rod.lengths + sphere.radius * 2,
-            rod.internal_forces,
             rod.external_forces,
             sphere.external_forces,
-            sphere.external_torques,
-            sphere.director[:, :, 0],
             rod.velocity_collection,
             sphere.velocity_collection,
             k,

tests/test_contact_utils.py

@@ -12,6 +12,7 @@
     _clip,
     _out_of_bounds,
     _find_min_dist,
+    _find_min_dist_cylinder_sphere,
     _aabbs_not_intersecting,
     _prune_using_aabbs_rod_cylinder,
     _prune_using_aabbs_rod_rod,