my_env.py

from robosuite.models import MujocoWorldBase
from robosuite.models.robots import Panda
from robosuite.models.grippers import gripper_factory
from robosuite.models.objects import BallObject
from robosuite.utils.mjcf_utils import new_joint
from mujoco_py import MjSim, MjViewer

world = MujocoWorldBase()

mujoco_robot = Panda()

gripper = gripper_factory('PandaGripper')
gripper.hide_visualization()
mujoco_robot.add_gripper(gripper)

mujoco_robot.set_base_xpos([0, 0, 0])
world.merge(mujoco_robot)

sphere = BallObject(
	name="sphere",
	size=[0.04],
	rgba=[0, 0.5, 0.5, 1]).get_collision()
sphere.append(new_joint(name='sphere_free_joint', type='free'))
sphere.set('pos', '1.0 0 1.0')
world.worldbody.append(sphere)

model = world.get_model(mode="mujoco_py")

sim = MjSim(model)
viewer = MjViewer(sim)
viewer.vopt.geomgroup[0] = 0 # disable visualization of collision mesh

for i in range(10000):
	sim.data.ctrl[:] = 0
	sim.step()
	viewer.render()