other files

Author: LeonLiu4

tests/test_rigid_physics.py

@@ -2200,6 +2200,36 @@ def test_urdf_mimic(show_viewer, tol):
     assert_allclose(gs_qpos[-1], gs_qpos[-2], tol=tol)
 
 
+@pytest.mark.required
+@pytest.mark.parametrize("backend", [gs.cpu])
+def test_gravity(show_viewer):
+    base_rpm = 14468.429183500699
+    scene = gs.Scene(
+        show_viewer=show_viewer,
+        sim_options=gs.options.SimOptions(
+            dt=0.01,
+            substeps=1,
+            gravity=[(0.0, 0.0, -9.8), (0.0, 0.0, -10.00)],
+        ),
+    )
+
+    drone = scene.add_entity(
+        gs.morphs.Drone(file="urdf/drones/cf2x.urdf", pos=(0, 0, 1.0)),
+    )
+
+    scene.build(n_envs=2)
+
+    for _ in range(500):
+        drone.set_propellels_rpm([[base_rpm, base_rpm, base_rpm, base_rpm], [base_rpm, base_rpm, base_rpm, base_rpm]])
+        scene.step()
+
+    first_pos = drone.get_dofs_position()[0, 2]
+    second_pos = drone.get_dofs_position()[1, 2]
+    assert_allclose(
+        second_pos, first_pos - 2.5, tol=scene.sim_options.dt
+    )  # Relax the tolerance due to time integration's error
+
+
 @pytest.mark.required
 @pytest.mark.parametrize("backend", [gs.cpu])
 def test_drone_hover_same_with_and_without_substeps(show_viewer, tol):